effort vs tour de force

effort and tour de force both are nouns.

Word	Noun	Adjective	Verb	Adverb
effort	Yes	No	No	No
tour de force	Yes	No	No	No

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

Other hyponyms of effort include derring-do, hit, rally, rallying, stunt.

effort (noun)	tour de force (noun)
earnest and conscientious activity intended to do or accomplish something	a masterly or brilliant feat
use of physical or mental energy; hard work
a notable achievement
a series of actions advancing a principle or tending toward a particular end