tumescence

Etymology

First attested 1725, from French tumescence, from Latin tumescēns (“swelling”), present participle of tumēscō (“to begin to swell”), from tumeō (“to swell”) + -ēscō (incohative suffix) (English -esce, in this form -escence), stem from Proto-Indo-European *tum-éh₁- (“to be swelling”), stative stem of *tum- (“to swell”).