only one; not one of several

a single red rose

the kingdom was ruled over by a single family

unmarried or not involved in a stable sexual relationship

a single mother

consisting of one part

the studio was a single large room

free from duplicity or deceit; ingenuous

a pure and single heart

an individual person or thing rather than part of a pair or a group

a hit for one run

(especially in tennis and badminton) a game or competition for individual players, not pairs or teams

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

choose someone or something from a group for special treatment

one newspaper was singled out for criticism

thin out (seedlings or saplings)

hand hoes are used for singling roots

reduce (a railway track) to a single line

the South Western line was singled west of Salisbury

hit a single

Cohen singled to centre