The Collaborative International Dictionary of English v.0.48:

manure \ma*nure"\ (m[.a]*n[=u]r"), n.
   Any matter which makes land productive; a fertilizing
   substance. Especially,, dung, the contents of stables and
   barnyards, decaying animal or vegetable substances, etc.
   --Dryden.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Manure \Ma*nure"\ (m[.a]*n[=u]r"), v. t. [imp. & p. p. Manured
   (m[.a]*n[=u]rd"); p. pr. & vb. n. Manuring.] [Contr, from
   OF. manuvrer, manovrer, to work with the hand, to cultivate
   by manual labor, F. man[oe]uvrer. See Manual, Ure,
   Opera, and cf. Inure.]
   1. To cultivate by manual labor; to till; hence, to develop
      by culture. [Obs.]
      [1913 Webster]

            To whom we gave the strand for to manure. --Surrey.
      [1913 Webster]

            Manure thyself then; to thyself be improved;
            And with vain, outward things be no more moved.
                                                  --Donne.
      [1913 Webster]

   2. To apply manure to; to enrich, as land, by the application
      of a fertilizing substance.
      [1913 Webster]

            The blood of English shall manure the ground.
                                                  --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

manure
    n 1: any animal or plant material used to fertilize land
         especially animal excreta usually with litter material
    v 1: spread manure, as for fertilization [syn: manure, muck]

Moby Thesaurus II by Grady Ward, 1.0:

39 Moby Thesaurus words for "manure":
   BM, ammonia, bowel movement, buffalo chips, ca-ca,
   castor-bean meal, commercial fertilizer, compost, coprolite,
   coprolith, cow chips, cow flops, cow pats, crap, defecation,
   dingleberry, dressing, droppings, dung, enrichener, feces,
   feculence, fertilizer, guano, jakes, movement, muck, night soil,
   nitrate, nitrogen, ordure, organic fertilizer, phosphate, sewage,
   sewerage, shit, stool, superphosphate, turd



Bouvier's Law Dictionary, Revised 6th Ed (1856):

MANURE, Dung. When collected in a heap, it is considered as personal
property, but, when spread, it becomes a part of the land and acquires the
character of real estate. Alleyn, 31; 2 Ired. R. 326.