A skid can be one of several things or conditions.

• In airplane operations during a turn if the combination of gravity and centrifugal force will cause a pendulum to swing toward the outside of the turn the airplane is said to be in a skid. (If toward the inside, the condition is called a slip.)

• In automobile and similar vehicle operations a loss of traction during braking or turning on either both front wheels, or both rear wheels, or all four wheels is called a skid. A skid may be induced by excessive braking, excessive turning force (due usually to excessive speed in the turn), or excessive power application in a turn (particularly in rear wheel drive vehicles). Skids usually occur as a result of excessive speed, braking, or power under conditions of poor traction due to ice, snow, or water on the pavement.

• The runners of a sledge (a device for transporting loads over ice or snow) are called skids.

• For removal of logs from a hilly forest a water channel may be bridged with transverse log segments to support and allow the movement of large logs downhill under the influence of gravity, or they may be placed on horizontal surfaces forming a rough trough to allow logs to be towed. Such a log path is called a skid road, subsequently corrupted to skid row, a term used as a metaphor for a neighborhood filled with derelict persons.

• It can also be a term used to refer to gangs of disenfranchised, delinquent youth, often blue-collar, who live in middle class suburbs and linger on the fringe of society.