Is it ensure, insure, or assure?
mid-13c., "fierce, ferocious;" c.1300, "wild, undomesticated, untamed" (of animals and places), from Old French sauvage, salvage "wild, savage, untamed, strange, pagan," from Late Latin salvaticus, alteration of silvaticus "wild," literally "of the woods," from silva "forest, grove" (see sylvan). Of persons, the meaning "reckless, ungovernable" is attested from c.1400, earlier in sense "indomitable, valiant" (c.1300).
"wild person," c.1400, from savage (adj.).
"to tear with the teeth, maul," 1880, from savage (adj.). Earlier "to act the savage" (1560s). Related: Savaged; savaging.
A young police officer eager to make arrests (1940s+ Police)