'Meditationes philosophicae de nonnullis ad poema pertinentibus' of 1735 works out esthetics as a particular discipline of sensual knowledge. The term itself appeared the first time in the unfinished work 'Aestetica' in 1750.
You mean as a source for what was there before during 18th century? For being honest I want to know in particular, if it had been received in its time or better in 1st half of 18th century.
Well the word "Esthétique" apparently made its first appearance in France in 1753, but if Élisabeth Décultot is correct the concept hardly had any impact. See her abstract here: