noun, na-adjective
faint smile; half smile
A subtle, restrained smile that is not a full laugh; often used when someone is amused but trying not to show it, or when the situation is awkward.
See also: 薄笑い (うすわらい)
彼は半笑いでその場をやり過ごした。
He got through the situation with a faint smile.
半笑いの表情が、彼女の本心を隠していた。
Her half-smile expression hid her true feelings.