troop, troupe

Troop or troop means a group or set of soldiers, police officers, or scouts--
The local boy scout troop is selling snacks to raise money for a camping trip.
Some of the soldiers were wounded while still on the troop transport.
Troop may also be a verb ( action word ), meaning to move in a group, or to march in something like a military style--
The students lined up to troop out onto the field.

Troupe or troupe ( rhymes with troop ) means a group or set of actors or performers--
The troupe played in each little town, usually to an enthusiastic audience.
When he was sixteen, he ran away and joined a circus troupe.

Now that you know that, you can say--
"The troop of motorcycle cops becomes a performing troupe once a year, when they put on a show to benefit the Police Athletic League."

Note--"trooper" means a member of a troop. "Trooper" is most commonly used to mean a state police or highway patrol officer--
He was pulled over by a state trooper, but he didn't get a ticket.
"Trouper" means a member of an acting or performing group, especially one who continues with a performance under adverse conditions--
She went on tonight even though she's been sick. She's a real trouper!
Note # 2-- "troops" usually means soldiers or members of the armed forces in general--
There's been civil unrest there; our government is thinking of sending troops.
"Troops" may also be the third person singular ( he, she, it ) form of the verb ( action word ) "troop", meaning to march in a military style--
The way he troops about the house, I almost feel like saluting him.
Note # 3--not to be confused with "trope", meaning a literary device, in which words are used in sense other than literal--
He was still learning the language, and each trope made a stumbling block.
He refused to understand the trope, and was sure that pearly teeth ought to be round.