shí​wǔ

fifteen

十五 shí​wǔ
fifteen numeral
the cardinal number fifteen

There are fifteen students in this class.

fifteenth numeral
the fifteenth day of a lunar month

The fifteenth day of the first lunar month is China's Lantern Festival.

Frequency

Movie subtitles
8.29 per million appears in 3% of films

Sources

Definitions
CC-CEDICT
Frequency data
SUBTLEX-CH