(computing) A system using multiple hard drives for the sharing or replication of data in order to increase data integrity, fault-tolerance or throughput.

(Britain) A form of civil protection (using closed-circuit television, control zones and restricted access) that effectively seals off city centres and financial districts; used in Northern Ireland and the City.

(idiomatic) To act in a haphazard or aimless way; to act frantically or without control.

An alliance and confederation of nine former Soviet republics: Armenia, Azerbaijan, Belarus, Kazakhstan, Kyrgyzstan, Moldova, Russia, Tajikistan and Uzbekistan formed as a successor to the Soviet Union.

(idiomatic, cricket) of a ball that pitches short of a good length; a ball that bounces closer to the bowler than the area of the pitch regarded as the best for dismissing or restricting the scoring of the batsman.

(medicine, of a prescription medication) Outside of regulatorily approved indications, but (unless otherwise specified) within the bounds of reasonable use as defined by a licensed prescriber.

(medicine, of a prescription medication) Outside of regulatorily approved indications, but (unless otherwise specified) within the bounds of reasonable use as defined by a licensed prescriber.

write off

(euphemistic, Scotland) To practise coitus interruptus, the withdrawal method of contraception. / Used other than figuratively or idiomatically: see get, off, at, Haymarket.

(military) That portion of a theater of war] which an army passes over in attaining its object.