Synonyms for Taper:

adj.

narrow (adjective)
taper off, thin down, thin out, whittle down, grow less.

n.

crater, slump, dip. candlestick, Japanese lantern, gaslight, chandelier, candelabra, Chinese Lantern. incendiary, spill, safety match, match, poker, live, matchstick, cord. light (noun)
sun.
light source (noun)
flame, Illuminator, star, floodlight, floor lamp, arc lamp, flare, moonbeam, light bulb, oil lamp, flashlight, spotlight, light, lantern, mercury-vapor lamp, klieg light, fire, fluorescent light, jack-o'-lantern, street lamp, candle, neon light, incandescent light, beacon, table lamp, lamp, pilot light, headlight, torch, sun, searchlight, desk light, Tungsten lamp, moon.
taper (noun)
candle, sharpen, wax light, point.

v.

change (verb)
sharpen, point.
decrease (verb)
drain, thin out, taper off, lessen, reduce, dwindle, narrow, diminish.
diminish (verb)
compact, crop, dwindle, clip, truncate, curtail, shear, abbreviate, trim, concentrate, lighten, contract, bob, deflate, weed, diminish, pare, decrease, deplete, downgrade, shave, reduce, condense, prune, shorten, lessen, cull, erode, nip, shrink, abridge, compress, drain, minimize, decrement.
recede (verb)
taper off.

Other synonyms:

Diminishment, cutback. abatement, slowdown, curtailment, diminution, reduction. Other relevant words:
abatement, cut, curtailment, slowdown, match, reduction, diminution, cord, slash, Diminishment, sharpen, slump, spill, narrow, point, cutback, thin out, taper off, wax light, dip.

Usage examples for taper

  1. The Disston saw also embodied an improved blade shape which made it " lighter and more convenient by giving it a greater taper to the point." – Woodworking Tools 1600-1900 by Peter C. Welsh
  2. And fitting, as he spake, A taper in his hold, Pursued: A murderer on the stake had died. – Strange Pages from Family Papers by T. F. Thiselton Dyer