noun
Etymology: base (IV)
1. : a metal or alloy (as zinc, lead, or brass) of comparatively low value and relatively inferior in certain properties (as resistance to corrosion) — opposed to noble metal
2. : the metal to which a coating or plating is applied : the metal existing underneath a coating or plating
3. : the chief constituent of any alloy
4. : the metal composing parts to be welded