- involving three directions, persons, etc.: a three-way conversation
- Elec. designating or of:
- a lightbulb with two filaments that can be switched on singly or together to produce three different levels of brightness
- a switch with three terminals, used to control a circuit from two different locations
- Having, permitting, or indicating passage in three directions: a three-way valve.
- Having three participants or ingredients: a three-way tie; three-way chili.
- a sexual act involving three people.
- Sexual activity involving three persons; a threesome; a menage Ã trois.