(rail transport) Having only a single track so that trains may only run in one direction at a time

(travel) A ticket entitling the holder to travel in one direction to a destination.

(music) The first single released from an album

Having one strand

(historical) A duel between single representatives of opposing armies, with the outcome accepted as the battle's outcome.

plural of single combat

A room that has one single bed.

Used to ask whether the interlocutor does or doesn't have a (romantic) partner.

(metalworking, manufacturing) A three-dimensional shape into which a thin flat sheet of material, e.g. metal, can be formed by bending alone, without stretching or compression.

Having an honest heart; straightforward, free from duplicity. / Devoted; unambivalent and dedicated.