Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
28th is an adjective meaning "coming next after the twenty-seventh in position". It carries one recorded sense.
coming next after the twenty-seventh in position
Definitions, synonyms and semantic relations for 28th come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.