upright vs jamb

upright and jamb both are nouns.

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

As nouns, jamb is a hyponym of upright; that is, jamb is a word with a more specific, narrower meaning than upright:

upright: a vertical structural member as a post or stake
jamb: upright consisting of a vertical side member of a door or window frame

Other hyponyms of upright include column, pillar, post, scantling, stud, scape, shaft, stile.

upright (noun)	jamb (noun)
a piano with a vertical sounding board	upright consisting of a vertical side member of a door or window frame
a vertical structural member as a post or stake

upright (adjective)	jamb (adjective)
upright in position or posture
of moral excellence
in a vertical position; not sloping