Origin of fifteenMiddle English fiftene from OE: see five and -teen
- The cardinal number equal to 14 + 1.
- The 15th in a set or sequence.
Origin of fifteenMiddle English fiftene from Old English fīftēne ; see penkwe in Indo-European roots.
From Middle English, from Old English fīftīene, fīftēne, from Proto-Germanic *fimftehun. Compare West Frisian fyftjin, Dutch vijftien, German fünfzehn, Danish femten.