Antibiotics and antibacterials are used as synonyms against chemical agents used for getting rid (kill or inhibit) of bacteria.

Whereas, antimicrobial is very broad term which I prefer to use. 

The word antibiotic does not sound good- "against life"

To be specific:

1. Antibiotic:  An antibiotic is an agent that either kills or inhibits the growth of a microorganism

2. Antibacterial: Anything that destroys bacteria or suppresses their growth or their ability to reproduce. 

Dear Godfred A Menezes

Thanks for your reply. 

I need to no if any antibiotic from chemical origin kills or inhibitis bactera, can be say it as antibacterial. Although regulatory agencies cattageriozed it as Antibiotics.

Yes Neeraj you can. U can say, all antibiotics are antibacterials but all antibacterials are not antibiotics. Hope you understood. 

Dear Ali Abdil Razzaq Muhammed Noori Aldallal 

There is many antibiotics which are produced by synthetically, like majority of macrolide antibiotics.

Antibiotics can be generally used drugs against any bacteria and mostly as allopathic medicines; antibacterials may also include other therapeutic regimens and modules like other systems of medicines and newer therapies like avian egg antibodies, cytokines, bacteriophages, bacteriocines, herbs etc. 

I agree with Ali Abdil Razzaq Muhammed Noori Aldallal , as he says both ills the bacteria but antibiotics are originated from microorganism other wise antimicrobial may also be synthetic or chemical origine

An antibiotic was originally defined as a substance, produced by one microorganism, which inhibited the growth of other microorganisms. The advent of synthetic methods has, however, resulted in a modification of this definition and an antibiotic now refers to a substance produced by a microorganism, or to a similar substance (produced wholly or partly by chemical synthesis), which in low concentrations inhibits the growth of other microorganisms. Chloramphenicol was an early example.Antimicrobial agents such as sulphonamides and the 4-quinolones, produced solely by synthetic means, are often referred to as antibiotics.

You are right Dr. Alaa, against the original definition of antibiotics, it include synthetis and semisynthetic ones too.

dear De Alaa , to my knowledge and that you referred previously, antibiotic refer to naturally produced substance that inhibit or kill bacteria. Did you mean that the term became broad to include synthetic one.تحياتي وحبي واشواقي لان انا اموت بالانتيبايوتك والجينات لان شغلي هذا بالماستر

An antibiotic is an agent that either kills or inhibits the growth of a microorganism.The term antibiotic was first used in 1942 by Selman Waksman and his collaborators in journal articles to describe any substance produced by a microorganism that is antagonistic to the growth of other microorganisms in high dilution. This definition excluded substances that kill bacteria but that are not produced by microorganisms (such as gastric juices and hydrogen peroxide). It also excluded synthetic antibacterial compounds such as the sulfonamides. Many antibacterial compounds are relatively small molecules with a molecular weight of less than 2000 atomic mass units.

Today antibiotics and antibacterials can be said to be synonyms. Their definitions now includes synthetic and semi-synthetic compounds. Synthetic and semi synthetic compounds are actually replacing the natural compounds for the production of commercial chemotherapeutic drugs.

An antibiotic is an agent that either kills or inhibits the growth of a cell (tumour, bacteria, fungi, etc.)

An antibacterial is an agent that either kills or inhibits the growth of bacteria.  ..........

personal opinion.

In layman's language antibiotics refers to anything (medicinal activity) that generally inhibits growth of  fungi, bacteria, virus, etc, whereas antibacterial refers to anything that specifically inhibits growth of bacteria alone.

Dear All

Thanks for giving your valuable suggestions.

Antibiotic are chemotherapeutic agent produce from microorganism, it can be from bacteria, fungi and etc, it has been processed through different methods , but antibacterial are any agent that have an inhibitory effect on bacterial only.

So, we can say all antibiotics are antibacterial, whereas all antibacterials are not antibiotics. So it is possible to use term antibacterials for antibiotics.

The terminology of Antimicrobial, antibiotic, antibacterial, should be more specific based on the two things i,e source of their origin (natural, semisynthetic or synthetic) and the type of organism  (bacteria, fungi, virus, parasite) against which it is effective. Antimicrobial agent  is any agent effective against any microorganism (bacteria, fungi, virus, parasite) and its original source may be natural, semisynthetic or synthetic. Antibiotic is any agent which was originally produced from microorganism and used against microorganisms ( to kill or inhibit their growth) in dilute quantity ( now it may be produced from natural , semisynthetic or synthetic way). Antibacterial is any agent  effective against bacteria its source may be any (natural ,semisynthetic , synthetic). Similarly antiviral or antifungal or antiprotozoal, or anthelmintic etc  are the antimicrobial agents effective against specific microorganism and their source may be any. EXAMPLES

Penicillin, Chloramphenicol,  Aminoglycosides : Antimicrobial, antibiotic, antibacterial (original source natural and effective against bacteria)

Sulphonamides, metronidazole, Quinolones:   Antimicrobial, antibacterial, antiprotozoal (but not antibiotic as its source is synthetic)

Ivermectin: Antimicrobial,  anthelmintic, endectocide, antibiotic (as its original  source is microorganism) but not antibacterial (as not effective against bacteria)

Antibacterial specifically refers to an inhibition of growth of bacteria, whereas antibiotics refer to a general inhibition of growth of microorganisms, which could include bacteria and viruses.

antibiotic are used to kill bacteria  while antibacterial is used to inhibit or kill bacteria So antibiotic against life 

On this same topic: Can someone help parse this:

I have heard chemotherapeutic agents (not cancer meds, but the use of chemicals as meds as theorized by Paul Ehlrich in early 20th century) described as "synthetic antibiotics"; elsewhere I have seen antibiotics only include drugs post-penicillin.

So is it correct to call chemotherapeutic agents, like sulpha drugs, or organo arsenicals (atoxyl) antibiotic?

On the etymology, interesting it note, that the origin of the term from botany from the (i think) late nineteenth century,  as the antagonistic relationship between two organisms. 

Antibiotics may includes (in addition to antibacterial action), antifungal, antiviral, antiprotozoal, and so on.

Antibiotic is the natural agents that produce by fungi or any other organsim that induce killing the bacterial, while antibacterial is semi-synthetic or synthetic products that kills bacteria

Antibiotics are the agents which is used to inhibits the growth of microorganism including bacteria, virus and fungus etc.

Antibacterials are the agents which is used to destroy the bacteria or inhibits the growth of bacteria only

Antibiotic mean ‘against life’ an agent that kills a microbial cell by simply disrupting an essential structure, or by blocking a critical metabolic function interferes with the growth and reproduction of microbial cell produced by one microorganism (Gilmore MS., 2002).

Antibiotics are often derived from moulds or are made synthetically and are absorbed into the body with the aim of tow function, killing bacteria called bactericidal or preventing their multiplication called bacteriostatic (Helen Nankervis.et al. 2016)

Antibiotics and antibacterial both attack bacteria, these terms mean two different things, antibiotics are medicines used to prevent and treat bacterial infections (AbdulRahman.et al.2017).

While Antimicrobial, Antibacterials are described as agents used to eliminate potentially harmful bacteria or disinfect surfaces. Unlike antibiotics, they are not used as medicines for humans or animals, but are found in products such as skincare creams, soaps, detergents, and household cleaners. (Russell, 2004).

The word “antibiotic” refers to substances produced by microorganisms that act against another microorganism. Thus, antibiotics do not include antimicrobial substances that are synthetic (sulfonamides and quinolones), or semisynthetic (methicillin and amoxicillin), or those which come from plants (quercetin and alkaloids) or animals (lysozyme).

All antibiotics are antibacterials but all antibacterials are not antibiotics. All antibiotics are medicines but all antibacterials are not medicines such as soaps and detergents have antibacterial actions but these are not medicines.