sour

Inaccurate in pitch.

“a false (or sour) note”

Having a sharp biting taste.

One of the four basic taste sensations; like the taste of vinegar or lemons.

Smelling of fermentation or staleness.

Showing a brooding ill humor.

“a sour temper”

In an unpalatable state.

“sour milk”

The property of being acidic.

The taste experience when vinegar or lemon juice is taken into the mouth.

A cocktail made of a liquor (especially whiskey or gin) mixed with lemon or lime juice and sugar.

Go sour or spoil.

“The milk has soured”

Make sour or more sour.