[1] : The Collaborative International Dictionary of English v.0.48

need \need\ n=ed, v. t. imp.  p. p. needed; p. pr.  vb.
   n. needing. see need, n. cf. as. n=ydan to force,
   goth. nauthornjan.
   to be in want of; to have cause or occasion for; to lack; to
   require, as supply or relief.
   1913 webster

         other creatures all day long
         rove idle, unemployed, and less need rest. --milton.
   1913 webster

   note: with another verb, need is used like an auxiliary,
         generally in a negative sentence expressing requirement
         or obligation, and in this use it undergoes no change
         of termination in the third person singular of the
         present tense. "and the lender need not fear he shall
         be injured." --anacharsis trans. .
         1913 webster
see also:
needed needing need 

[2] : The Collaborative International Dictionary of English v.0.48

needed \needed\ adj.
   necessary; as, provided them with all needed equipment.
   opposite of unnecessary.

   syn: needful, required, requisite.
        wordnet 1.5
see also:
unnecessary 

[3] : WordNet (r) 2.0

needed
     adj : necessary for relief or supply; "provided them with all
           things needful" syn: needful, required, requisite
see also:
needful required requisite 

Needed >> N Words
Needed, definition of term: Needed
needed_pag1.html

As Needed >> A Words
As Needed, definition of term: As Needed
as+needed_pag1.html