1.  adequacy(n = noun.attribute) adequateness - the quality of being able to meet a need satisfactorily:; "he questioned the adequacy of the usual sentimental interpretation of the Golden Rule"
is a kind of satisfactoriness
Antonym: inadequacy

2.  adequacy(n = noun.attribute) sufficiency - the quality of being sufficient for the end in view; "he questioned the sufficiency of human intelligence"
is a kind of quality
has particulars: ampleness
Antonym: inadequacy

   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]

N  sufficiency, adequacy, enough, withal, satisfaction, competence, no less, quantum sufficit, Q, S, mediocrity, fill, fullness, plenitude, plenty, abundance, copiousness, amplitude, galore, lots, profusion, full measure, good measure pressed down and running, over, luxuriance, affluence, fat of the land, a land flowing with milk and honey, cornucopia, horn of plenty, horn of Amalthaea, mine, outpouring, flood, tide, repletion, satiety, sufficient, enough, adequate, up to the mark, commensurate, competent, satisfactory, valid, tangible, measured, moderate, full, ample, plenty, plentiful, plenteous, plenty as blackberries, copious, abundant, abounding, replete, enough and to spare, flush, choke-full, chock-full, well-stocked, well- provided, liberal, unstinted, unstinting, stintless, without stint, unsparing, unmeasured, lavish, wholesale, rich, luxuriant, affluent, wantless, big with, unexhausted, unwasted, exhaustless, inexhaustible, sufficiently, amply Adj, full, in abundance, with no sparing hand, to one's heart's content, ad libitum, without stint, cut and come again, das Beste ist gut genug.

N  utility, usefulness, efficacy, efficiency, adequacy, service, use, stead, avail, help, applicability, subservience, function, value, worth, money's worth, productiveness, cui bono, utilization, step in the right direction, common weal, commonwealth public good, public interest, utilitarianism, useful, of use, serviceable, proficuous, good for, subservient, conducive, subsidiary, advantageous, profitable, gainful, remunerative, worth one's salt, valuable, prolific, adequate, efficient, efficacious, effective, effectual, expedient, applicable, available, ready, handy, at hand, tangible, commodious, adaptable, of all work, usefully, pro bono publico.