Definitions:
consisting of or involving three items or people

three times as much or as many

a thing that is three times as large as usual or is made up of three standard units or items

a sporting contest in which each side has three players.

a system of change-ringing using seven bells, with three pairs changing places each time.

a hit which enables the batter to reach third base.

become three times as much or as many

hit a triple