'abhorrer' originates from Latin, specifically the word 'abhorrēre,' where 'ab-' meant 'away from' and 'horrēre' meant 'to shudder.'

'abhorrēre' transformed into the Old French word 'abhorrer,' and eventually became the modern English word 'abhorrer' through Middle English.

Initially, it meant 'to shudder away from something,' but over time it evolved into its current meaning of 'to detest or loathe intensely.'