pollex vs thumb

pollex and thumb both are nouns.

Word	Noun	Adjective	Verb	Adverb
pollex	Yes	No	No	No
thumb	Yes	No	Yes	No

As nouns, pollex and thumb are synonyms defined as:

pollex (noun)	thumb (noun)
the thick short innermost digit of the forelimb	the part of a glove that provides a covering for the thumb
	a convex molding having a cross section in the form of a quarter of a circle or of an ellipse
	the thick short innermost digit of the forelimb

pollex (verb)	thumb (verb)
	feel or handle with the fingers
	travel by getting free rides from motorists
	look through a book or other written material