adjective
- next after the twelfth; being the ordinal number for 13.
- being one of 13 equal parts.
noun
- a thirteenth part, especially of one (1/13).
- the thirteenth member of a series.
adjective
- (usually prenominal)
- coming after the twelfth in numbering or counting order, position, time, etc; being the ordinal number of thirteen: often written 13th
- (as noun)Friday the thirteenth
noun
-
- one of 13 equal or nearly equal parts of something
- (as modifier)a thirteenth part
- the fraction equal to one divided by 13 (1/13)
- music
- an interval of one octave plus a sixthSee also interval (def. 5)
- short for thirteenth chord
adj.early 14c., þriteenþe, from thirteen + -th (1), replacing forms from Old English þteoteoða. Cf. Old Norse þrettande, Danish trettende, Swedish trettonde, Old Frisian threttinde, Dutch dertiende, Old High German dritto-zehanto, German dreizehnte.