Surveillance of the immediate surroundings using one's senses.

A style of gaming in first-person shooters (FPS), where realistic ("real-world") settings are simulated by the gaming engine (to the best of its ability) and players use authentic military tactics to accomplish goals in the game.

The space covered by a steamer in turning 180° out of her original course.

plural of tactical diameter

The placing of a vote for a candidate other than one's first choice, for strategic reasons, in an attempt to prevent an undesirable outcome.

plural of tactical warning

(military) A warning of an ongoing or immediately impending attack.

(military) The loading of troops and equipment in a way that facilitates their tactical operations, rather than merely making the maximal use of the available space.

plural of tactical air commander

(military) The shore-based officer (aviator) responsible to the landing force commander for control and coordination of air operations within the landing force commander's area of operations when control of these operations is passed ashore.