Source : Webster's Revised Unabridged Dictionary (1913)

Troweled \Trow"eled\
   Formed with a trowel; smoothed with a trowel; as, troweled
   stucco, that is, stucco laid on and ready for the reception
   of paint. [Written also {trowelled}.]

Source : WordNet®

trowel
     n : a small hand tool with a handle and flat metal blade; used
         for scooping or spreading plaster or similar materials
     v : use a trowel on; for light garden work or plaster work
     [also: {trowelling}, {trowelled}]

trowelled
     See {trowel}