A person or substance that deterges; something that cleanses or washes away impurities.
From Latin detergere (to wipe away) plus -er (agent suffix), meaning 'one who or that which cleanses.'
In older medical texts, a deterger could be a poultice, salve, or even a barber-surgeon—anyone or anything trusted to clean a wound, showing how the word captured an entire profession before modern antiseptics existed.
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