noun

1. A feeling of apprehension, doubt, fear etc.

2. A sudden sickly feeling; queasiness.

3. A prick of the conscience; a moral scruple, a pang of guilt. (Now often in negative constructions.)

   “This lawyer has no qualms about saving people who are on the wrong side of the law.”

Synonyms: compunction, misgiving, scruple, unease, uneasiness

verb

1. To have a sickly feeling.