IPA: /ˈklæm.ɪ.li/
KK: /ˈklæmɪli/
In a way that feels damp and cool, often making you uncomfortable.
The air in the basement was clammily cold, making everyone shiver.
Clammily is derived from the adjective "clammy" (from Middle English *clammi*, meaning damp or moist) with the adverbial suffix "-ly" (meaning in a manner of). The word "clammily" describes the manner of being damp or moist, often in an unpleasant way.
Think of the word 'clammy' which means damp or moist, and remember that 'clammily' describes doing something in a damp or moist manner.