elbow grease vs travail

elbow grease and travail both are nouns.

Word	Noun	Adjective	Verb	Adverb
elbow grease	Yes	No	No	No
travail	Yes	No	Yes	No

As nouns, elbow grease and travail are synonyms defined as:

Other synonyms of elbow grease include effort, exertion, sweat.

elbow grease (noun)	travail (noun)
use of physical or mental energy; hard work	use of physical or mental energy; hard work
	concluding state of pregnancy; from the onset of contractions to the birth of a child

elbow grease (verb)	travail (verb)
	work hard