noun
: a metal or alloy of low density (as aluminum, magnesium, titanium and beryllium, and alloys composed predominantly of one or more of these metals)
noun
: a metal or alloy of low density (as aluminum, magnesium, titanium and beryllium, and alloys composed predominantly of one or more of these metals)
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012