From The Collaborative International Dictionary of English v.0.48 [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) 3.0 (2006) [wn]:
The dictionary definitions are retrieved from a local copy of two of the open source DICT dictionaries. Click here for the database copyright information. DEFINE.COM is registered as an educational NONPROFIT corporation. We aim to please around here. We believe in using positive reinforcement to get things done. We make suggestions that are intended to make life more enjoyable. We think about efficiency, automation, security, privacy, social and ecological responsibility and positive humanitarian ethics and values. We are benevolent. DO NO HARM is our motto.
In the interest of FULL DISCLOSURE, there is a particularly interesting SCREENSHOT of the home page here.
I don't want Uncle Sam having my SIM Card PRIVATE keys.