"morbid swelling," early 15c., from Medieval Latin tumefaccionem (nominative tumefaccio), noun of action from Latin tumefactus, from tumescere "begin to swell, swell up" (see tumescence).
Entries linking to tumefaction
tumescence n.
1725, from French tumescence, from Latin tumescentem (nominative tumescens) "swelling," present participle of tumescere "begin to swell, swell up," figuratively "grow excited, become enraged," inceptive of tumere "to swell" (from PIE root *teue- "to swell"), with inchoative suffix -escere.