作用

zuòyòng
  1. to act on; to affect
  2. action; function; activity
  3. impact; result; effect
  4. purpose; intent
  5. (suffix) -ation, -tion etc, as in 抑制作用 yìzhìzuòyòng, inhibition

CEDICT

Entry Composition

1 作 zuò
  1. to do; to engage in
  2. to write; to compose
  3. to pretend; to feign
  4. to regard as; to consider to be
  5. to be; to act the part of
  6. to feel (itchy, nauseous etc)
  7. writings; works
2 用 yòng
  1. to use; to make use of; to employ
  2. (coverb) with; using
  3. to need; to have to (usu. used in the negative or in questions)
  4. usefulness; utility
  5. (bound form) expense; outlay
  6. (courteous) to eat; to drink
  7. (literary) hence; therefore