squad vs firing squad

squad and firing squad both are nouns.

Word	Noun	Adjective	Verb	Adverb
squad	Yes	No	No	No
firing squad	Yes	No	No	No

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

squad: a smallest army unit
firing squad: a squad formed to fire volleys at a military funeral or to carry out a military execution

Other hyponyms of squad include firing party.

squad (noun)	firing squad (noun)
a cooperative unit (especially in sports)	a squad formed to fire volleys at a military funeral or to carry out a military execution
a smallest army unit
a small squad of policemen trained to deal with a particular kind of crime