adequacy

from WordNet (r) 3.0 (2006)

adequacy
    n 1: the quality of being able to meet a need satisfactorily:
         "he questioned the adequacy of the usual sentimental
         interpretation of the Golden Rule" [syn: {adequacy},
         {adequateness}] [ant: {inadequacy}, {inadequateness}]
    2: the quality of being sufficient for the end in view; "he
       questioned the sufficiency of human intelligence" [syn:
       {sufficiency}, {adequacy}] [ant: {deficiency}, {inadequacy},
       {insufficiency}]

from The Collaborative International Dictionary of English v.0.48

Adequacy \Ad"e*qua*cy\, n. [See {Adequate}.]
   The state or quality of being adequate, proportionate, or
   sufficient; a sufficiency for a particular purpose; as, the
   adequacy of supply to the expenditure.
   [1913 Webster]