1725, from French tumescence, from Latin tumescentem (nominative tumescens) "swelling," present participle of tumescere "begin to swell," from tumere "to swell" (see thigh) + inchoative suffix -escere. The earliest attested form of the word in English is tumefaction (1590s).
tumescence tu·mes·cence (tōō-měs'əns, tyōō-)
A swelling or an enlargement.
A swollen condition.
A swollen part or organ.
tumescent tu·mes·cent (tōō-měs'ənt, tyōō-)
Becoming swollen; swelling.