'allayer' originates from the verb 'allay', which comes from Middle English 'aleyen', derived from Old English 'ālecgan', where 'ā-' meant 'away' and 'lecgan' meant 'to lay'.

'ālecgan' transformed into the Middle English 'aleyen', and eventually became the modern English word 'allay'.

Initially, it meant 'to lay down or put aside', but over time it evolved into its current meaning of 'to alleviate or reduce'.