taper
verb
1 it has roundish leaves which taper at the tip:
narrow, thin (out), become narrow, become narrower, become thin, become thinner, come to a point, attenuate.
▷antonyms thicken, swell.
2 at first there was a flurry of meetings, but these soon tapered off:
decrease, lessen, dwindle, diminish, reduce, subside, decline, die off, die away, die down, fade, peter out, wane, ebb, abate, wind down, slacken (off), fall off, drop off, trail off/away, let up, thin out;
weaken, wilt, slump, plummet, fall off a cliff.
▷antonyms increase.