PERISPORE
Per"i*spore, n. (Bot.)

Defn: The outer covering of a spore.

PERISSAD
Per"is*sad, a. Etym: [Gr. (Chem.)

Defn: Odd; not even; — said of elementary substances and of radicals whose valence is not divisible by two without a remainder. Contrasted with artiad.

PERISSE
Per"isse, v. i.

Defn: To perish. [Obs.] Chaucer.

PERISSODACTYL
Per`is*so*dac"tyl, n. (Zoöl.)

Defn: One of the Perissodactyla.

PERISSODACTYLA
Per`is*so*dac"ty*la, n. pl. Etym: [NL., from Gr. (Zoöl.)

Defn: A division of ungulate mammals, including those that have an odd number of toes, as the horse, tapir, and rhinoceros; — opposed to Artiodactyla.