Definition of acetates:
(n) :
(organic chemistry) Any ester or salt of acetic acid.
(n) :
A transparent sheet used for overlays, whether of cellulose acetate or (loosely) any macroscopically similar plastic.
(n) :
Cellulose acetate.
(n) :
In full acetate disc: a disc of aluminium covered in a wax used to make demonstration copies of a phonograph record.