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

tapering \ta"pering\, a.
   becoming gradually smaller toward one end. --
   ta"peringly, adv.
   1913 webster
see also:
ta"peringly 

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

taper \ta"per\, v. i. imp.  p. p. tapered; p. pr.  vb. n.
   tapering.
   to become gradually smaller toward one end; as, a sugar loaf
   tapers toward one end.
   1913 webster
see also:
tapered tapering 

[3] : WordNet (r) 2.0

tapering
     adj 1: gradually narrowed toward a point; "a tall tapering spire"
            syn: tapered
     2: becoming gradually narrower; "long tapering fingers";
        "trousers with tapered legs" syn: tapered, narrowing
     3: gradually decreasing until little remains syn: dwindling,
         tapering off
     n : the act of gradually lowering the size or amount; "the
         doctor prescribed the tapering of the dose"
see also:
tapered narrowing dwindling tapering off 

[4] : Moby Thesaurus II by Grady Ward, 1.0

38 moby thesaurus words for "tapering":
   acanthoid, acanthous, acicular, acuate, aculeate, aculeiform,
   acuminate, acute, barbed, coarctation, cone-shaped, constriction,
   contraction, cornuted, cusped, cuspidate, hispid, horned, horny,
   mucronate, narrowing, needle-pointed, needle-sharp, pointed,
   pronged, sharp-pointed, spiculate, spiked, spiky, spined, spinous,
   spiny, stricture, taper, tapered, tined, toothed, unbated

Tapering >> T Words
Tapering, definition of term: Tapering
tapering_pag1.html

Tapering Off >> T Words
Tapering Off, definition of term: Tapering Off
tapering+off_pag1.html