Valediction in a sentence as a noun

Additionally, e-mail incurs a seemingly heavy time penalty to send -- some kind of greeting and valediction always must be present. On IRC, doing so is amounts to almost wasting everyone's time if you have an issue to bring up.

Valediction definitions

noun

a farewell oration (especially one delivered during graduation exercises by an outstanding member of a graduating class)

See also: valedictory

noun

the act of saying farewell