多久

duōjiǔ
  1. (of time) how long?
  2. (not) a long time

CEDICT

Entry Composition

1 多 duō
  1. many; much; more; a lot of
  2. too many; in excess
  3. (after a numeral) ... odd
  4. how (to what extent) (Taiwan pr. duó)
  5. (bound form) multi-; poly-
2 久 jiǔ (of a period of time) long