Wordnet 3.0
NOUN (1)
1. 
 a small hand tool with a handle and flat metal blade; 
 used for scooping or spreading plaster or similar materials; 
VERB (1)
1. 
 use a trowel on; 
 for light garden work or plaster work; 
The Collaborative International Dictionary of English v.0.48:
Trowel \Trow"el\, n. [OE. truel, OF. truele, F. truelle, LL.
   truella, L. trulla, dim. of trua a ladle; probably akin to
   Gr. ? a stirrer, ladle, G. quirl a stirrer, MHG. twirel, OHG.
   dwiril, Icel. [thorn]vara, AS. [thorn]wiril. Cf. Twirl.]
   1. A mason's tool, used in spreading and dressing mortar, and
      breaking bricks to shape them.
      [1913 Webster]
   2. A gardener's tool, somewhat like a scoop, used in taking
      up plants, stirring the earth, etc.
      [1913 Webster]
   3. (Founding) A tool used for smoothing a mold.
      [1913 Webster]
   Trowel bayonet. See Spade bayonet, under Spade.
   Fish trowel. See Fish slice, under Fish.
      [1913 Webster]
WordNet (r) 3.0 (2006):
trowel
    n 1: a small hand tool with a handle and flat metal blade; used
         for scooping or spreading plaster or similar materials
    v 1: use a trowel on; for light garden work or plaster work