Saddle-backed Definition

sad'lbakt
adjective
Having a low, hollow back curved like a saddle, as some horses.
Webster's New World
Having a concave outline, as a ridge between peaks.
Webster's New World

Having a saddle-shaped marking; saddleback.

Wiktionary
verb

Simple past tense and past participle of saddleback.

Wiktionary
adverb

(of riding a horse) With a saddle, rather than bare-backed.

Wiktionary