the.com/puffiness

means A swollen, bloated fullness in the skin, especially the face, caused by fluid retention — from tears, salt, sleep, or time.

from Straightforward stuff: 'puff' goes back to Old English 'pyffan,' a word that imitated the short burst of breath or wind it described — a puff of air, a puff of smoke. By the 1600s 'puffy' meant swollen or distended, like something inflated with air, and 'puffiness' followed as the noun for that bloated state. No hidden twist here — it's onomatopoeia all the way down, your face literally described as if someone blew air under the skin.