On the HSK 3 vocabulary list, at CEFR level B1.

zhōng ㄓㄨㄥ

    • handleless cup goblet
    • to concentrate (one's affection etc)

      bound form

    • a (large) bell (CL:架[jia4])
    • clock (CL:座[zuo4])
    • amount of time o'clock (CL:點|点[dian3],分[fen1],秒[miao3]) (as in 三點鐘|三点钟[san1 dian3 zhong1] "three o'clock" or "three hours" or 五分鐘|五分钟[wu3 fen1 zhong1] "five minutes" etc)

Where 钟 is used

Sources