Any of the immunological spaces between the arteries and veins (not capillaries) and pia mater that can be expanded by leukocytes.

plural of spare wheel

A spark produced by the jumping of electricity across a permanent gap.

(mineralogy, informal) potassic feldspar

A field spaniel of a breed similar to the Clumber spaniel, but shorter in body and of a liver-and-white or black-and-white colour.

plural of spark coil

An induction coil used for producing sparks, as in an internal combustion engine. / A self-induction coil used to increase the spark in an electric gas-lighting apparatus.

(billiards) In the balk-line game, any of eight spaces, 7 × 3½ inches, lying along a cushion and bisected transversely by a balk line. Object balls in an anchor space are treated as in balk.

(card games, usually in the plural) In auction bridge, a spade when spades are trumps under the condition that every trick over six taken by the successful bidder has a score value of 9.

(physics, dated) The dark space within the negative-pole glow at the cathode of a vacuum tube, observed only when the pressure is low enough to give a striated discharge.