'useful'はこちらの項目にも見つかりました。
英語の見出し語に対する説明:
asset
- come in handy
- convenience
- convenient
- dead
- expedient
- gadget
- gizmo
- good
- good use
- handy
- help
- helpful
- impractical
- inexpedient
- life
- marketable skill
- necessity
- not be good for
- of some help
- over the hill
- pragmatic
- purposive
- resource
- right people
- service
- serviceable
- shelf life
- stand sb in good stead
- tap into
- usable
- useless
- utilitarian
- utilizable
- work
- workhorse