資料來源 : pyDict

無用的,無效的,無益的

資料來源 : Webster's Revised Unabridged Dictionary (1913)

Useless \Use"less\, a.
   Having, or being of, no use; unserviceable; producing no good
   end; answering no valuable purpose; not advancing the end
   proposed; unprofitable; ineffectual; as, a useless garment;
   useless pity.

         Not to sit idle with so great a gift Useless, and
         thence ridiculous.                       --Milton.

   Syn: Fruitless; ineffectual.

   Usage: {Useless}, {Fruitless}, {Ineffectual}. We speak of an
          attempt, effort, etc., as being useless when there are
          in it inherent difficulties which forbid the hope of
          success, as fruitless when it fails, not from any such
          difficulties, but from some unexpected hindrance
          arising to frustrate it; as, the design was rendered
          fruitless by the death of its projector. Ineffectual
          nearly resembles fruitless, but implies a failure of a
          less hopeless character; as, after several ineffectual
          efforts, I at last succeeded.

                Useless are all words Till you have writ
                ``performance'' with your swords. The other is
                for waiving.                      --Beau. & Fl.

                Waiving all searches into antiquity, in relation
                to this controversy, as being either needless or
                fruitless.                        --Waterland.

                Even our blessed Savior's preaching, who spake
                as never man spake, was ineffectual to many.
                                                  --Bp.
                                                  Stillingfleet.
          -- {Use"less*ly}, adv. -- {Use"less*ness}, n.

資料來源 : WordNet®

useless
     adj 1: having no beneficial use or incapable of functioning
            usefully; "a kitchen full of useless gadgets"; "she is
            useless in an emergency" [ant: {useful}]
     2: not useful; "a curiously unhelpful and useless manual"