ω

Symbol

 * 1)  angular velocity
 * 2)  acentric factor
 * 3)  The first (countably) infinite ordinal number, its corresponding cardinal number ℵ0 or the set of natural numbers (the latter of which are often defined to equal the former).

Etymology
From Ω curved upward.

Letter

 * 1) Lower-case omega, the 24th letter of the ancient Greek alphabet. It represented the long open-mid back rounded vowel . It is preceded by ψ.

Derived terms
See also omega

Etymology 1
.

Letter

 * 1) The lower case letter omega (ωμέγα), the 24th and last letter of the modern Greek alphabet.

Etymology 2
.

Interjection

 * 1) oh!