'dampen' originates from English, formed from the adjective 'damp' + the verb-forming suffix '-en'.

'damp' appeared in Middle English (from forms such as 'damp'/'damp(e)') and the verb 'dampen' developed later by adding '-en' to create an action meaning 'to make damp'.

Initially, it meant 'to make wet or moist', but over time it also came to mean 'to reduce intensity or strength' (for feelings, sound, etc.).