https://www.etymonline.com/word/dampen#etymonline_v_29154 https://www.etymonline.com/word/dampen#etymonline_v_29154 > dampen (v.) 1630s, "to dull or deaden, ma

https://www.etymonline.com/word/dampen#etymonline_v_29154 https://www.etymonline.com/word/dampen#etymonline_v_29154 > dampen (v.) 1630s, "to dull or deaden, make weak" (force, enthusiasm, ardor, etc.), from damp (adj.). Meaning "to moisten, make humid" is recorded from 1827. https://www.etymonline.com/word/dampener#etymonline_v_36691 https://www.etymonline.com/word/dampener#etymonline_v_36691 > dampener (n.) > "one who or that which dampens," It's an older phrasing, but it checks out.