不時

不时
bùshí
  1. from time to time
  2. now and then
  3. occasionally
  4. frequently

CEDICT

Entry Composition

1 不 bù
  1. no; not so
  2. (bound form) not; un-
2 時 shí
  1. o'clock
  2. time
  3. when
  4. hour
  5. season
  6. period