qualm

n.

1. Doubt

   scruple, misgiving, doubt, compunction, reservation, uneasiness, apprehension, hesitation, hesitancy, indecision, pang, twinge, twinge of conscience, equivocalness, second thought, funny feeling*; see also doubt 2.

2. Nausea

   faintness, dizziness, queasiness; see illness 1.

qualm implies a painful feeling of uneasiness arising from a consciousness that one is or may be acting wrongly I had qualms about leaving the children alone in the house; scruple implies doubt or hesitation arising from difficulty in deciding what is right, proper, just, etc. to break a promise without scruple; compunction implies a twinge of conscience for wrongdoing, now often for a slight offense to have no compunctions about telling a white lie; misgiving implies a disturbed state of mind resulting from a loss of confidence as to whether one is doing what is right misgivings of conscience