petite vs diminutive

petite and diminutive both are nouns.

Word	Noun	Adjective	Verb	Adverb
petite	Yes	Yes	No	No
diminutive	Yes	Yes	No	No

As adjectives, petite and diminutive are synonyms defined as:

Other synonyms of petite include bantam, flyspeck, lilliputian, midget, tiny.

petite (noun)	diminutive (noun)
a garment size for short or slender women	a word that is formed with a suffix (such as -let or -kin) to indicate smallness

petite (adjective)	diminutive (adjective)
very small	very small