intumescence (n.) Look up intumescence at Dictionary.com
"swollen state, expansion," 1650s, from French intumescence (17c.), from Latin intumescere "to swell up, rise, be elevated," of sounds, "grow louder," figuratively, "grow excited, become enraged," from in- "in" (from PIE root *en "in") + tumescere "begin to swell, swell up," figuratively "grow excited, become enraged," inceptive of tumere "to swell" (from PIE root *teue- "to swell"), with inchoative suffix -escere.