troop vs shock troops

troop and shock troops both are nouns.

Word	Noun	Adjective	Verb	Adverb
troop	Yes	No	Yes	No
shock troops	Yes	No	No	No

As nouns, shock troops is a hyponym of troop; that is, shock troops is a word with a more specific, narrower meaning than troop:

troop: a group of soldiers
shock troops: soldiers who are specially trained and armed to lead an assault

troop (noun)	shock troops (noun)
a group of soldiers	soldiers who are specially trained and armed to lead an assault
an orderly crowd
a unit of Girl or Boy Scouts
a cavalry unit corresponding to an infantry company

troop (verb)	shock troops (verb)
move or march as if in a crowd
march in a procession in a public place