strive vs tug

strive is not a noun while tug is a noun.

Word	Noun	Adjective	Verb	Adverb
strive	No	No	Yes	No
tug	Yes	No	Yes	No

As verbs, tug is a hypernym of strive; that is, tug is a word with a broader meaning than strive:

Other hypernyms of strive include drive, labor, labour, push.

strive (noun)	tug (noun)
	a sudden abrupt pull
	a powerful small boat designed to pull or push larger ships

strive (verb)	tug (verb)
to exert much effort or energy	struggle in opposition
attempt by employing effort	pull hard
	pull or strain hard at
	move by pulling hard
	carry with difficulty
	tow (a vessel) with a tug
	strive and make an effort to reach a goal