concourse vs ruck

concourse and ruck both are nouns.

Word	Noun	Adjective	Verb	Adverb
concourse	Yes	No	No	No
ruck	Yes	No	Yes	No

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

Other hyponyms of concourse include hive, horde, host, legion, herd.

concourse (noun)	ruck (noun)
a coming together of people	a crowd especially of ordinary or undistinguished persons or things
a wide hallway in a building where people can walk	an irregular fold in an otherwise even surface (as in cloth)
a large gathering of people

concourse (verb)	ruck (verb)
	become wrinkled or drawn together