似笑非笑
sì​xiào​fēi​xiào

faint smile

  1. 似 sì adjective
    to resemble
    (bound form) to be similar to; to look like; to resemble
  2. 笑 xiào verb
    to smile or laugh
    to have a happy expression on one's face or make sounds expressing joy; to smile; to laugh
  3. 非 fēi verb
    not be
    to not be; to not belong to; equivalent to 是 shì in its negative form
  4. 笑 xiào verb
    to smile or laugh
    to have a happy expression on one's face or make sounds expressing joy; to smile; to laugh