From The Collaborative International Dictionary of English v.0.44 [gcide]:
Useful \Use"ful\, adjective 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.
From WordNet (r) 2.0 [wn]:
From Moby Thesaurus II by Grady Ward, 1.0 [moby-thes]:
117 Moby Thesaurus words for "useful": advantageous, advisable, agential, agentival, agentive, aidful, appropriate, assisting, auspicious, banausic, becoming, befitting, beneficial, benevolent, bon, bonny, brave, braw, bueno, capital, cogent, commendable, commodious, conducive, congruous, constructive, contributory, convenient, decent, desirable, effective, elegant, employable, estimable, excellent, expedient, facilitating, fair, famous, favorable, favoring, feasible, felicitous, fine, fit, fitten, fitting, forwarding, fructuous, fruitful, functional, furthersome, gainful, good, good for, goodly, grand, handy, happy, healthy, helpful, instrumental, intermediary, kind, laudable, likely, mediating, mediatorial, meet, ministerial, ministering, nice, noble, of general utility, of help, of service, of use, opportune, pleasant, politic, positive, practicable, practical, pragmatical, productive, profitable, promoting, proper, propitious, recommendable, regal, remedial, right, royal, salutary, seasonable, seemly, serviceable, skillful, sortable, sound, splendid, subservient, suitable, therapeutic, timely, to be desired, toward, usable, utilitarian, valid, valuable, very good, virtuous, well-timed, wise, worthwhile
Define.com is a registered nonprofit corporation dedicated solely to the global public interest and the advancement of humanity. It belongs to all of us who have a desire to promote electronic democracy, science, creativity, imagination, reason, critical thinking, peace, race and gender equality, civil rights, equal access to education, personal liberty, free speech, animal rights, compassionate and nonviolent parenting, social and economic justice, global monetary reform, Secular Humanism, cognitive liberty and a permanent cessation of The War on Drugs.
Let's see what we can do if we put our heads together.0