What type of noun appears in all capital letters in TEAM?

Answer 1

The word 'team' is both a noun (team, teams) and a verb (team, teams, teaming, teamed).

The noun 'team' is a singular, common, concretenoun; a word for a number of persons associated together in work or an activity; two or more animals used to pull the same vehicle or piece of machinery.

You may have expected the answer to be 'a collective noun'; however, the noun 'team' is only a collective noun when it is used in that function, such as a team of workmen, or a team of oxen. A 'collective noun' is a function of a noun, not a form of a noun.

Answer 2

The word team is a singular, common, collective noun.