environ v.

word-forming element meaning "in; into," from French and Old French en-, from Latin in- "in, into" (from PIE root *en "in"). Typically assimilated before -p-, -b-, -m-, -l-, and -r-. Latin in- became en- in French, Spanish, Portuguese, but remained in- in Italian.

Also used with native and imported elements to form verbs from nouns and adjectives, with a sense "put in or on" (encircle), also "cause to be, make into" (endear), and used as an intensive (enclose). Spelling variants in French that were brought over into Middle English account for parallels such as ensure/insure, and most en- words in English had at one time or another a variant in in-, and vice versa.

1580s, "to change direction" (originally of the wind; 1610s of a ship), from French virer "to turn" (12c.), of uncertain origin, perhaps (Diez) from the Latin stem vir- in viriae (plural) "bracelets." Gamillscheg finds von Wartburg's derivation of it from a Vulgar Latin contraction of Latin vibrare "to shake" to be nicht möglich. Related: veered, veering.