n. 25B6; verb
the moon is waning : DECREASE, diminish, dwindle.
their support was waning : DECLINE, diminish, decrease, dwindle, shrink, tail off, ebb, fade (away), lessen, peter out, fall off, recede, slump, flag, weaken, give way, wither, evaporate, die out; poetic/literary evanesce.
wax, grow.
25A0; on the wane DECLINING, decreasing, diminishing, dwindling, shrinking, contracting, tapering off, subsiding, ebbing, fading away, dissolving, petering out, winding down, falling off, on the way out, receding, flagging, melting away, crumbling, withering, disintegrating, evaporating, dying out.