<p><strong>Adjective</strong></p><ul><li>only one in number; one only; unique; sole: a single example.</li><li>Synonyms: particular, distinct</li><li>of, relating to, or suitable for one person only: a single room.</li><li>solitary or sole; lone: He was the single survivor.</li><li>Synonyms: isolated</li><li>unmarried or not in a romantic relationship: a single man.</li><li>Synonyms: unwed</li><li>pertaining to the unmarried state: the single life.</li><li>of or noting a parent who brings up a child or children alone, without a partner.</li><li>of one against one, as combat or fight.</li><li>consisting of only one part, element, or member: a single lens.</li><li>sincere and undivided: single devotion.</li><li>separate, particular, or distinct; individual: Every single one of you must do your best.</li><li>It's the single most important thing.</li><li>uniform; applicable to all: a single safety code for all manufacturers.</li><li>(of a bed or bedclothes) twin-size.</li><li>(of a flower) having only one set of petals.</li><li>British: of standard strength or body, as ale, beer, etc.</li><li>Compare double.</li><li>(of the eye) seeing rightly.</li></ul><p><strong>Verb</strong></p><ul><li><p>(used with object)</p><ul><li>singled, singling: to pick or choose (one) from others (usually followed by out): to single out a fact for special mention.</li><li>Synonyms: select</li><li>Baseball: to cause the advance of (a base runner) by a one-base hit.</li><li>to cause (a run) to be scored by a one-base hit (often followed by in or home).</li></ul></li><li><p>(used without object)</p><ul><li>singled, singling: Baseball: to hit a single.</li></ul></li></ul><p><strong>Noun</strong></p><ul><li>one person or thing; a single one.</li><li>Synonyms: individual</li><li>an accommodation suitable for one person only, as a hotel room or a table at a restaurant: to reserve a single.</li><li>a ticket for a single seat at a theater.</li><li>British: a one-way ticket.</li><li>a steam locomotive having one driving wheel on each side.</li><li>singles: people who are unmarried or not in a romantic relationship, especially if relatively young: It's not uncommon for singles to feel lonely on Valentine Day.</li><li>Baseball: Also called one-base hit: a base hit that enables a batter to reach first base safely.</li><li>singles (used with a singular verb): a match with one player on each side, as a tennis match.</li><li>Golf: twosome (def 4).</li><li>Cricket: a hit for which one run is scored.</li><li>Informal: a one-dollar bill.</li><li>Music: a phonograph record, CD, or cassette usually having two songs: I probably won't buy the single.</li><li>one of the songs recorded on a single: a hit single.</li><li>a song released or promoted separately from the rest of the album to which it belongs: A viral video put that single back on the charts.</li><li>Often singles.</li><li>Textiles: reeled or spun silk that may or may not be thrown; a one-ply yarn of any fiber that has been drawn and twisted.</li></ul>