Is it ensure, insure, or assure?
early 13c., from Anglo-French and Old North French veil (Old French voile) "a head-covering," also "a sail," from Latin vela, plural of velum "sail, curtain, covering," from PIE root *weg- "to weave a web." Vela was mistaken in Vulgar Latin for a feminine singular noun. To take the veil "become a nun" is attested from early 14c.
late 14c., from Old French veler, voiller, from Latin velare "to cover, veil," from velum (see veil (n.)). Figurative sense of "to conceal" (something immaterial) is recorded from 1530s. Related: Veiled; veiling.
A membranous covering or part, especially a membrane surrounding the young mushrooms of certain basidiomycete fungi. In some species the membrane (called a partial veil) extends only from the stalk to the cap. As the cap expands, the veil breaks, leaving a ring called an annulus on the stalk and often scalelike pieces on the cap. These veil remnants are important for identifying species of mushrooms.