Swollen
Old English swellan (verb), of Germanic origin; related to German schwellen . Current senses of the noun date from the early 16th century; the informal adjectival use derives from noun swell (sense 5 of the noun) (late 18th century).
wiktionary
From Middle English swollen, i-swolle, y-swolle, yswolle, ȝeswollen, from Old English swollen, ġeswollen, from Proto-Germanic *swullanaz, past participle of Proto-Germanic *swellaną(“to swell”). Cognate with West Frisian swollen(“swollen”), Dutch gezwollen(“swollen”), German geschwollen(“swollen”), Swedish svullen(“swollen”).
etymonline
swollen (adj.)
"swelled, marked by swelling in any sense," early 14c., past-participle adjective from strong conjugation of swell (v.); from Old English geswollen, past participle of swellan. More commonly used than swelled.
