In very simple words, hypothesis is an assumption/intuition that you have formed in your mind which you intend to prove in your study. Thus, you need to form 2 types of hypotheses, one is called the Null Hypothesis (which you want to DISPROVE) & the other is the Alternative Hypothesis (your objective is to prove this right). Very simple example (and already a fact), you feel from your general experience that there is a relationship/association between tobacco chewing and oral cancer (lets say we are talking about a time when this fact had not been proven). So your hypothesis is " There is an association between tobacco and oral cancer". Thus, if you have to prove it statistically your Null Hypothesis is " There is NO ASSOCIATION between, tobacco and oral cancer" and your Alternative Hypothesis is "There is an association between tobacco and oral cancer". Your aim is to REJECT the Null Hypothesis coz once that gets rejected you automatically prove your AH. This is the general explanation. I dont know if I  am able to answer in reference to your context. I am not aware if there a separate meaning for hypothesis with respect to the field of engineering.

Hypothesis is a "Guess" (singular format--1 guess that you are arguing to prove through reasoning and proof )

Hypotheses is (plural more than 1 guess) 

Rewritten

Eg: " Concept learning can be formulated as a problem of searching through predefined space of potential (multiple guesses or arguments) for the (one main reasoned guess or argument) that best fits the training examples."

Definitions are linked below.

Hope this helps.

http://dictionary.reference.com/browse/hypothesis?s=t

Sekaran (2003) wrote:

“A hypothesis can be defined as a logically conjectured relationship between two or more variables expressed in the form of a testable statement. Relationships are conjectured on the basis of the network of associations established in the theoretical framework formulated for the research study. By testing the hypotheses and confirming the conjectured relationships, it is expected that solutions can be found to correct the problem encountered.”

Please refer Sekaran’s book for more details.

Reference

Sekaran, U., 2003. Research methods for business: A skill building approach. John Wiley & Sons.