Emily Dickinson Lexicon

AL-LAY', v.t. [Sax. alecgan, alegan, to lay, to set, to depress, lecgan, to lay, to cast or strike down; G. legen, D. leggen, to lay; Gr. λεγω. The Fr. allier, to alloy, Sp. ligar, seems to be directly from the L. ligo, to bind; but this may be the same word differently applied, that is, to set, to fix, to make fast, to unite. Allay and alloy were formerly used indifferently; but I have recognized an entire distinction between them, applying alloy to metals.]

1. To make quiet; to pacify or appease; as, to allay the tumult of the passions, or to allay civil commotions.
2. To abate, mitigate, subdue or destroy; as, to allay grief or pain. Females, who soften and allay the bitterness of adversity. – Rawle.
3. To obtund or repress as acrimony; as, to allay the acrid qualities of a substance.
4. Formerly, to reduce the purity of; as, to allay metals. But, in this sense, alloy is now exclusively used. [See Alloy.]