incalescence
noun
in·ca·les·cence ˌin-kə-ˈle-sᵊn(t)s 
ˌiŋ-
: a growing warm or ardent
incalescent
ˌin-kə-ˈle-sᵊnt
adjective ˌiŋ-
Word History
Etymology
Latin incalescere to become warm, from in- + calescere to become warm, inchoative of calēre to be warm — more at lee
First Known Use
1646, in the meaning defined above