unconcerned adj.
VERBS act, appear, be, look, seem, sound I tried to act unconcerned.
ADV. very | completely, quite, totally | relatively | apparently, seemingly
PREP. about They appeared completely unconcerned about what they had done. | by He was apparently unconcerned by his failure to gain a university place.
You can also check other dicts: unconcerned (English, 中文解释 ), wordnet sense, Collins Definition