(music) A 45 RPM vinyl record with one song on side A and one on side B. / (music) A popular song released and sold (on any format) nominally on its own though usually having at least one extra track.

To identify or select one member of a group from the others; generally used with out, either to single out or to single (something) out.

(uncountable) The property of being single. / (countable) The result or product of being single.

plural of singling

simple past tense and past participle of single out

(computing) The action of pushing the button on a mouse once in order to perform a different task that would be performed from a double-click or triple-click.

Suitable for, or restricted to, only one gender.

plural of single crystal

plural of single bed

Describing an experiment (usually medical) in which some information which might influence the trial is withheld from particular participants until the experiment is complete. Most commonly, information about treatment groups is withheld from subjects, but not the administrators.