Webster's Revised Unabridged Dictionary · 1913

Serenade

Serenade , noun

[French sérénade, Italian serenata, probably from Latin serenus serene (compare Serene), misunderstood as a derivative from Latin serus late. Compare Soirée.]

(a)
(Music) Music sung or performed in the open air at nights; -- usually applied to musical entertainments given in the open air at night, especially by gentlemen, in a spirit of gallantry, under the windows of ladies.
(b)
(Music) A piece of music suitable to be performed at such times.

Serenade , transitive verb

To entertain with a serenade.

Serenade , intransitive verb

To perform a serenade.