As a verb: Wash up at the sink in the laundry room before you all troop in here to eat.
As a noun: The troop of scouts showed much bravado about spending their first night in tents in the woods.
The troop disbanded after the accident.
I troop myself
The little old lady really picked up her pace when she saw the Boy Scout troop! Some primates gather in what is termed a troop.
"Shoot the troop of soldiers from the stoop."
"A" Troop was the only Troop from the 12th Cavalry sent to Vietnam.
The hyenas quickly abandoned the wounded antelope when they were confronted by a troop of monkeys. Telling a classroom full of children that there will be no ice cream runs the risk of having them behave like a troop of monkeys.
The troop's courageous efforts inspire everyone. or The troops' courageous efforts inspire everyone.
The troop of soldiers returned triumphantly after routing the enemy.
The tired troop trudged past. We trudged all day through the oppressive heat of the jungle only to find the edge of the desert.
Sgt. Harrington had the troop assemble at 5:00 a.m. for inspection.
petrol
As a noun, troop has two meanings, one a singular noun and one the more typical group noun. As both refer to people, they are concrete nouns. troop - a group of scouts, or soldiers troop - a single soldier (trooper) -- very rarely used