Qualm n. : Sickness; disease; pestilence; death.

Qualm n. : A sudden attack of illness, faintness, or pain; an agony.

Qualm n. : Especially, a sudden sensation of nausea.

Qualm n. : A prick or scruple of conscience; uneasiness of conscience; compunction.

Example:
What is your biggest Qualm about the 6th generation Maxima?

Taxonomy
qualm, Merriam-Webster Online Dictionary, Dictionary, webster, Word Games, doubt, fear, conscience, Webster Online Dictionary with audio pronunciations, demur, scruples, glossary, english, language, ESL, Search, Etymology, origin unknown.

Defination from the web:
qualm from the Merriam-Webster Online Dictionary with audio pronunciations, thesaurus, Word of the Day, and word games. ... synonyms qualm, scruple, compunction, demur mean a misgiving about what one is doing or going to do. ...