thumb vs hitchhike

thumb is a noun but hitchhike is not a noun.

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

As verbs, thumb and hitchhike are synonyms defined as:

Other synonyms of thumb include hitch.

thumb (noun)	hitchhike (noun)
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

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