• (typically of something regarded as good) become smaller, fewer, or less; decrease

Synonyms: decrease, reduce, get smaller, grow smaller, lessen, get less, diminish, wane, dwindle, contract, shrink, fall off, taper off, tail off, peter out

• politely refuse (an invitation or offer)

Synonyms: turn down, reject, brush aside, refuse, rebuff, spurn, disdain, look down one's nose at, repulse, repudiate, dismiss, forgo, deny oneself, pass up, refuse to take advantage of, turn one's back on

• (especially of the sun) move downwards

Synonyms: go down, sink, decline, descend, drop, subside

• (in the grammar of Latin, Greek, and certain other languages) state the forms of (a noun, pronoun, or adjective) corresponding to case, number, and gender

• a gradual and continuous loss of strength, numbers, quality, or value

Synonyms: reduction, decrease, downturn, downswing, lowering, devaluation, depreciation, lessening, diminishing, diminution, slackening, waning, dwindling, fading, ebb, falling off, abatement, drop, slump, plunge, tumble, deterioration, degeneration, degradation, shrinkage, shrinking, withering, atrophy, weakening, enfeeblement, fall, failure, death, decay, decaying, waning, declining, on the decline, decaying, crumbling, collapsing, atrophying, failing, disappearing, dying, moribund, past its prime, obsolescent