Webster’s Revised Unabridged Dictionary · 1913 Perisperm Per′i·sperm (·spẽrm), n. [F. périsperme. See Peri-, and Sperm.] (Bot.) The albumen of a seed, especially that portion which is formed outside of the embryo sac. — Per′i·sper′mic (#), a. ‹ Perisome Perispheric ›