(automotive) A position in the four-stroke combustion process wherein the piston is at the bottommost point in its stroke.

plural of youth detention center

plural of top dead center

plural of wilderness treatment center

plural of world trade center

(military) The principal air operations installation (ship-based) from which all aircraft and air warning functions of tactical air operations are controlled. Also called Navy TACC.

plural of tactical air control center

plural of three-center two-electron bond

(chemistry) Any of several forms of extended covalent bond, deficient in one electron, joining three atoms.