Definitions
1.NounA feeling of apprehension, doubt, fear etc. .mw-parser-output .defdate{font-size:smaller}
2.NounA sudden sickly feeling; queasiness.
3.NounA prick of the conscience; a moral scruple, a pang of guilt."This lawyer has no qualms about saving people who are on the wrong side of the law."
4.NounMortality; plague; pestilence.
5.NounA calamity or disaster.
6.VerbTo have a sickly feeling.