Querulous means complaining in an annoying, whiny way, especially about small things that don't really matter much. A querulous person finds fault constantly, often in a petulant tone that grates on others.

Imagine a classmate who complains endlessly: the classroom is too cold, then too hot, the assignment is too long, the pencil sharpener is too loud, lunch came too late, recess ended too early. That's querulous behavior. The complaints never stop, and the tone is whiny rather than constructive.

The word captures both what someone is doing (complaining) and how they sound doing it (irritating and whiny). You might notice a querulous quality in someone's voice when they're tired or grumpy: that nasal, fretful tone that makes even reasonable concerns sound tiresome.

Being querulous is different from raising legitimate concerns. If the fire alarm is broken, speaking up isn't querulous; it's responsible. But complaining that your orange has too many seeds, your book has too many pages, and your shoelaces are the wrong shade of white? That's querulous.