elbow grease vs trouble

elbow grease and trouble both are nouns.

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

As nouns, trouble is a hyponym of elbow grease; that is, trouble is a word with a more specific, narrower meaning than elbow grease:

elbow grease (noun)	trouble (noun)
use of physical or mental energy; hard work	an effort that is inconvenient
	a source of difficulty
	an event causing distress or pain
	an angry disturbance
	a strong feeling of anxiety
	an unwanted pregnancy

elbow grease (verb)	trouble (verb)
	cause bodily suffering to and make sick or indisposed
	disturb in mind or make uneasy or cause to be worried or alarmed
	move deeply
	to cause inconvenience or discomfort to
	take the trouble to do something; concern oneself