undeveloped vs vestigial

undeveloped and vestigial both are adjectives.

Word	Noun	Adjective	Verb	Adverb
undeveloped	No	Yes	No	No
vestigial	No	Yes	No	No

undeveloped (adjective)	vestigial (adjective)
not developed, mature, or fully formulated	not fully developed in mature animals
not developed, improved, exploited or used