The Collaborative International Dictionary of English v.0.48:

Need \Need\ (n[=e]d), v. t. [imp. & p. p. Needed; p. pr. & vb.
   n. Needing.] [See Need, n. Cf. AS. n[=y]dan to force,
   Goth. nau[thorn]jan.]
   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]

Moby Thesaurus II by Grady Ward, 1.0:

65 Moby Thesaurus words for "needing":
   appetitive, arrested, bankrupt in, bare of, bereft of, callow,
   defective, deficient, denuded of, deprived of, desiderative,
   desireful, desiring, desirous, destitute of, devoid of, eager,
   embryonic, empty of, failing, for want of, forlorn of, hoping,
   hormic, hypoplastic, immature, in arrear, in arrears, in default,
   in default of, in short supply, in want of, inadequate, incomplete,
   infant, lacking, lascivious, libidinal, libidinous, lickerish,
   lustful, missing, optative, out of, out of pocket, part, partial,
   patchy, scant, scant of, scanty, scrappy, short, short of, shy,
   shy of, sketchy, tempted, unblessed with, underdeveloped,
   undeveloped, unpossessed of, void of, wanting, wishing