single

Concise Oxford English Dictionary © 2008 Oxford University Press:
single/ˈsɪŋɡl/

▶adjective

• 1 only one; not one of several.

  ■ regarded as distinct from others in a group.

  ■ [with neg.] even one (used for emphasis): they didn't receive a single reply.

  ■ designed or suitable for one person.

• 2 not involved in a stable romantic or sexual relationship.

• 3 consisting of one part.

  ■ (of a flower) having only one whorl of petals.

• 4 Brit. (of a ticket) valid for an outward journey only.

• 5 archaic free from duplicity or deceit: a pure and single heart.

▶noun

• 1 a single person or thing.

• 2 a short record with one song on each side.

• 3 US informal a one-dollar note.

• 4 Cricket a hit for one run.

  ■ Baseball a hit which allows the batter to proceed safely to first base.

• 5 (singles) (especially in tennis and badminton) a game or competition for individual players.

• 6 Bell-ringing a system of change-ringing in which one pair of bells changes places at each round.

▶verb

• 1 (single someone/thing out) choose someone or something from a group for special treatment.

• 2 thin out (seedlings or saplings).

• 3 reduce (a railway track) to a single line.

• 4 Baseball hit a single.

  ■ cause (a run) to be scored by hitting a single.

  ■ advance (a runner) by hitting a single.

– derivatives
singledom noun,
singleness noun,
singly adverb.

– origin ME: via OFr. from L. singulus, rel. to simplus ‘simple’.