Having four sides and four equal angles.
- Having four equal sides and four right angles; square.
- Marked by firm, unwavering conviction or expression; forthright: a foursquare refusal to yield.
- In a forthright manner; squarely.
- A child's game in which each of four players stands in one of four boxes drawn on the ground in a two-by-two grid and must bounce a ball into another player's box without holding the ball or stepping out of bounds.