effort vs nisus

effort and nisus both are nouns.

Word	Noun	Adjective	Verb	Adverb
effort	Yes	No	No	No
nisus	Yes	No	No	No

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

effort: earnest and conscientious activity intended to do or accomplish something
nisus: an effortful attempt to attain a goal

effort (noun)	nisus (noun)
earnest and conscientious activity intended to do or accomplish something	an effortful attempt to attain a goal
use of physical or mental energy; hard work
a notable achievement
a series of actions advancing a principle or tending toward a particular end