The cardinal number occurring after fourteen (14) and before sixteen (16).

plural of fifteen

(UK, informal) A film assigned an age rating of 15, those under 15 not being permitted to view it. / (bibliography, informal) A book printed in the 15th century.

plural of fifteener

The property of being fifteen.

(UK, fandom slang) The practice of adding swearing to an English anime dub in order to get a higher age classification, which may attract more buyers.

The start of the sixteenth hour of the day on the 24-hour clock i.e. 15:00. / The number one thousand five hundred. / The year 1500.

Alternative spelling of 15 minutes

Synonym of quinceanera

(colloquial, US, Canada) The amount of body weight (thought to be 15 pounds) gained by a student during their first year of college.