v. 1 a decline, wane, ebb, dwindle, diminish, decrease The magnetic field rapidly decays when the power is removed b decline, waste away, atrophy, weaken, wither, degenerate, deteriorate, disintegrate; crumble Her great beauty decayed quickly 2 rot, decompose, moulder, putrefy, spoil; turn, go bad, go off The flesh has decayed and only a skeleton remains
n. 3 decline, weakening, failing, fading, deterioration, decadence, degeneration, wasting, atrophy, dilapidation, disintegration, collapse; downfall The buildings were in an advanced state of decay 4 rot, rotting, decomposition, mould, putrefaction, mortification The decay has weakened the timbers supporting the bridge