Definition of "pegasi"

But, I think it will be too risky to try and steal horses, unipegs, pegasi, or unicorns. There are spells cast on the animals to keep track of them.

2004, Myles Brandon Hibbett, Zephyr Spheres and the Lost Spell, Lincoln: iUniverse, page 49

There were three draia — one for luggage, including gifts — and twenty-two pegasi to carry them, plus a dozen more who would fly with them.

2010 November 2, Robin McKinley, Pegasus, New York: Putnam Juvenile, ch. 11