adjective

unable to concentrate because one is preoccupied by something worrying or unpleasant.

Charlotte seemed too distracted to give him much attention

preoccupied,diverted,inattentive,vague,absorbed,engrossed,abstracted,distrait,distant,absent,absent-minded,faraway,bemused,confused,bewildered,perplexed,puzzled,agitated,flustered,ruffled,disconcerted,discomposed,nonplussed,befuddled,mystified,troubled,pestered,harassed,worried,tormented,miles away,in a world of one’s own,not with it,fazed,hassled,in a flap