1. (v. i.) Acute; sharp; piercing; having or emitting a sharp, piercing tone or sound; -- said of a sound, or of that which produces a sound.

2. (n.) A shrill sound.

3. (v. i.) To utter an acute, piercing sound; to sound with a sharp, shrill tone; to become shrill.

4. (v. t.) To utter or express in a shrill tone; to cause to make a shrill sound.