Related Words

Keystone Sack: Second base.

Sack Mix: The amount of Portland cement in a cubic yard of concrete mix. Generally, 5 or 6 sack is required in a foundation wall.

Sackbut: Early brass instrument, ancestor of the trombone.

Sack: Tackling a ball carrier who intends to throw a forward pass. A sack is also awarded if a player forces a fumble of the ball, or the ball carrier to go out of bounds, behind the line of scrim . . . View Full Definition

Keystone Species: A predator at the top of a food web, or discrete subweb, capable of consuming organisms of more than one trophic level beneath it

Keystone Predator: The dominant predator or the top predator that has a major influence on community structure. For example, sea otters are a keystone predator in kelp beds. Sea otters eat urchins that feed on . . . View Full Definition

Keystone Frame: An American term to describe a diamond-type frame in which the engine serves as part of the structure.