endosperm (n.)

word-forming element meaning "inside, within, internal," from Greek endon "in, within" (from PIE *en-do-, extended form of root *en "in").

"male seminal fluid," late 14c., probably from Old French esperme "seed, sperm" (13c.) and directly from Late Latin sperma "seed, semen," from Greek sperma "the seed of plants, also of animals," literally "that which is sown," from speirein "to sow, scatter," from PIE *sper-mn-, from root *sper- "to spread, to sow" (see sparse). Sperm bank is attested from 1963. For sperm whale see spermaceti.