intumescent,a.|ɪntjuːˈmɛsənt| [ad. L. intumēscent-em, pr.pple. of intumēscĕre: see intumesce.] Swelling up; becoming tumid. 1870Rolleston Anim. Life 119 The integument is..thickened and intumescent.1875Lyell Princ.Geol. II. ii. xxvii. 68 The..lava..appears to have been a long time in an intumescent state.