keep vs defend

keep is a noun but defend is not a noun.

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

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

keep: stop (someone or something) from doing something or being in a certain state
defend: be on the defensive; act against an attack

keep (noun)	defend (noun)
the main tower within the walls of a medieval castle or fortress
a cell in a jail or prison
the financial means whereby one lives

keep (verb)	defend (verb)
prevent (food) from rotting	argue or speak in defense of
prevent the action or expression of	state or assert
stick to correctly or closely	be on the defensive; act against an attack
maintain by writing regular records	protect against a challenge or attack
supply with necessities and support	protect or fight for as a champion
hold and prevent from leaving	fight against or resist strongly
retain possession of	be the defense counsel for someone in a trial
look after; be the keeper of; have charge of
retain rights to
maintain for use and service
have as a supply
store or keep customarily
stop (someone or something) from doing something or being in a certain state
allow to remain in a place or position or maintain a property or feature
conform one's action or practice to
behave as expected during of holidays or rites
cause to continue in a certain state, position, or activity
supply with room and board
maintain in safety from injury, harm, or danger
fail to spoil or rot
continue a certain state, condition, or activity
to rear