defend vs uphold

defend and uphold both are verbs.

Word	Noun	Adjective	Verb	Adverb
defend	No	No	Yes	No
uphold	No	No	Yes	No

As verbs, uphold is a hyponym of defend; that is, uphold is a word with a more specific, narrower meaning than defend:

defend (verb)	uphold (verb)
argue or speak in defense of	stand up for; stick up for; of causes, principles, or ideals
state or assert	support against an opponent
be on the defensive; act against an attack	keep or maintain in unaltered condition; cause to remain or last
protect against a challenge or attack
protect or fight for as a champion
fight against or resist strongly
be the defense counsel for someone in a trial