leash vs restraint

leash and restraint both are nouns.

Word	Noun	Adjective	Verb	Adverb
leash	Yes	No	Yes	No
restraint	Yes	No	No	No

As nouns, restraint is a hypernym of leash; that is, restraint is a word with a broader meaning than leash:

As nouns, restraint is a hypernym of leash; that is, restraint is a word with a broader meaning than leash:

leash: restraint consisting of a rope (or light chain) used to restrain an animal
restraint: a device that retards something's motion

Other hypernyms of leash include constraint.

leash (noun)	restraint (noun)
a figurative restraint	the act of controlling by restraining someone or something
restraint consisting of a rope (or light chain) used to restrain an animal	a device that retards something's motion
the cardinal number that is the sum of one and one and one	discipline in personal and social activities
	lack of ornamentation
	a rule or condition that limits freedom
	the state of being physically constrained

leash (verb)	restraint (verb)
fasten with a rope