it is not a noun; troop is a noun. Troop is a common noun.
common noun
is troop a comman noun
The noun 'troop' is a singular, common, concrete noun; a word for a group of people or things. The noun 'troop' functions as a collective noun for: a troop of Brownies a troop of dogfish a troop of gorillas a troop of kangaroos a troop of monkeys a troop of soldiers
"Park Avenue" is a proper noun, because it is a place. Proper nouns like this should always be capitalized.
Common
It is a proper noun, because it is the name of a specific thing.
proper
Neem tree is a common noun. Proper nouns are the unique names of people, places, or things. Common nouns are the words for general things. If a common noun is part of a name, it becomes a proper noun. Pronouns always replace proper and common nouns.
Proper noun
it's a common noun. a proper noun would be Spider-Man.
Pencil proper or common noun
Proper noun or common noun