1640s, "payment for saving a ship from wreck or capture," from French salvage (15c.), from Old French salver "to save" (see save (v.)). The general sense of "the saving of property from danger" is attested from 1878. Meaning "recycling of waste material" is from 1918, from the British effort in World War I.
1889, from salvage (n.). Related: Salvaged; salvaging.
To steal; loot; liberate (WWI Army)