tu·mes·cent 
(t-mĕsənt, ty-)
(t-mĕsənt, ty-)adj.
1. Somewhat tumid.
2. Becoming swollen; swelling.
[Latin tumēscēns, tumēscent-, present participle of tumēscere, to begin to swell, inchoative of tumēre, to swell; see teuə- in the Appendix of Indo-European roots.]