Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
15th is an adjective meaning "coming next after the fourteenth and just before the sixteenth in position". It carries one recorded sense.
Definitions, synonyms and semantic relations for 15th come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.