ponderosity

from WordNet (r) 3.0 (2006)

ponderosity
    n 1: the property of being large in mass [syn: {heft},
         {heftiness}, {massiveness}, {ponderousness}, {ponderosity}]

from The Collaborative International Dictionary of English v.0.48

Ponderosity \Pon`der*os"i*ty\, n.; pl. {Ponderosities}. [OF.
   ponderosit['e].]
   The quality or state of being ponderous; weight; gravity;
   heaviness, ponderousness; as, the ponderosity of gold. --Ray.
   [1913 Webster]