bouquet vs posy

bouquet and posy both are nouns.

Word	Noun	Adjective	Verb	Adverb
bouquet	Yes	No	No	No
posy	Yes	No	No	No

As nouns, bouquet and posy are synonyms defined as:

bouquet and posy: an arrangement of flowers that is usually given as a present

Other synonyms of bouquet include corsage, nosegay.

bouquet (noun)	posy (noun)
an arrangement of flowers that is usually given as a present	an arrangement of flowers that is usually given as a present
a pleasingly sweet olfactory property