A shrill sound.
Sharp or keen to the senses.
Having a shrill voice.
Fierce, loud, strident.
High-pitched and piercing.
To make a shrill noise.
A voiceless consonant.
An irrational number, especially one expressed using the √ symbol.
unvoiced; voiceless
Involving surds, or irrational numbers; not capable of being expressed in rational numbers.