doorpost vs jamb

doorpost and jamb both are nouns.

Word	Noun	Adjective	Verb	Adverb
doorpost	Yes	No	No	No
jamb	Yes	No	No	No

As nouns, jamb is a hypernym of doorpost; that is, jamb is a word with a broader meaning than doorpost:

doorpost: a jamb for a door
jamb: upright consisting of a vertical side member of a door or window frame

doorpost (noun)	jamb (noun)
a jamb for a door	upright consisting of a vertical side member of a door or window frame