usability
         n 1: the quality of being able to provide good service [syn:
               {serviceability}, {serviceableness}, {usableness},
               {useableness}, {usability}]

English Dictionary: useable	by the DICT Development Group
From WordNet (r) 3.0 (2006) [wn]:
usable adj capable of being put to use; "usable byproducts" [syn: useable, usable] fit or ready for use or service; "the toaster was still functional even after being dropped"; "the lawnmower is a bit rusty but still usable"; "an operational aircraft"; "the dishwasher is now in working order" Synonym(s): functional, usable, useable, operable, operational convenient for use or disposal; "the house is available after July 1"; "2000 square feet of usable office space" Synonym(s): available, usable, useable
From WordNet (r) 3.0 (2006) [wn]:
usableness n the quality of being able to provide good service [syn: serviceability, serviceableness, usableness, useableness, usability]
From WordNet (r) 3.0 (2006) [wn]:
useable adj fit or ready for use or service; "the toaster was still functional even after being dropped"; "the lawnmower is a bit rusty but still usable"; "an operational aircraft"; "the dishwasher is now in working order" Synonym(s): functional, usable, useable, operable, operational capable of being put to use; "usable byproducts" Synonym(s): useable, usable convenient for use or disposal; "the house is available after July 1"; "2000 square feet of usable office space" Synonym(s): available, usable, useable
From WordNet (r) 3.0 (2006) [wn]:
useableness n the quality of being able to provide good service [syn: serviceability, serviceableness, usableness, useableness, usability]
From WordNet (r) 3.0 (2006) [wn]:
useful adj being of use or service; "the girl felt motherly and useful"; "a useful job"; "a useful member of society" Synonym(s): useful, utile Antonym(s): useless having a useful function; "utilitarian steel tables" Synonym(s): utilitarian, useful
From WordNet (r) 3.0 (2006) [wn]:
usefully adv in a useful manner; "extra money could be usefully spent on this project" Antonym(s): uselessly
From WordNet (r) 3.0 (2006) [wn]:
usefulness n the quality of being of practical use [syn: utility, usefulness] Antonym(s): inutility, unusefulness, uselessness
From Webster's Revised Unabridged Dictionary (1913) [web1913]:
Usable \Us"a*ble\, a.       Capable of being used.
From Webster's Revised Unabridged Dictionary (1913) [web1913]:
Useful \Use"ful\, a.       Full of use, advantage, or profit; producing, or having power       to produce, good; serviceable for any end or object; helpful       toward advancing any purpose; beneficial; profitable;       advantageous; as, vessels and instruments useful in a family;       books useful for improvement; useful knowledge; useful arts.                   To what can I useful!                              --Milton.
From Webster's Revised Unabridged Dictionary (1913) [web1913]:
Usefully \Use"ful*ly\, adv.       In a useful manner.
From Webster's Revised Unabridged Dictionary (1913) [web1913]:
Usefulness \Use"ful*ness\, n.       The quality or state of being useful; utility;       serviceableness; advantage. --Addison.          Syn: Utility; value; profit. See {Utility}.
From The Free On-line Dictionary of Computing (15Feb98) [foldoc]:
usability          The effectiveness, efficiency, and satisfaction       with which users can achieve tasks in a particular environment       of a product.   High usability means a system is: easy to learn       and remember; efficient, visually pleasing and fun to use; and       quick to recover from errors.          {(http://www.orrnet.com/)}.          (1999-04-01)