in·tu·mesce 
(ĭn′t-mĕs, -ty-)
(ĭn′t-mĕs, -ty-)intr.v. in·tu·mesced, in·tu·mesc·ing, in·tu·mesc·es
1. To swell or expand; enlarge.
2. To bubble up, especially from the effect of heating.
[Latin intumēscere : in-, intensive pref.; see IN-2 + tumēscere, to begin to swell, inchoative of tumēre, to swell; see teuə- in the Appendix of Indo-European roots.]