The term 'acetyl suffix' refers to two words that are formed by adding the suffix '-ette' or '-ist' to the word 'acetyl'. The suffix '-ette' is a French diminutive ending, usually used to indicate a small or feminine version of something. For example, 'CIGARETTE' is a diminutive of 'CIGAR'. The suffix '-ist' is used to indicate someone who practices or is an expert in a certain field. For example, a 'CHEMIST' is someone who practices chemistry. Therefore, the two words formed by adding the acetyl suffix are 'acetyl-ette' and 'acetyl-ist'.