From a derivative of kaio; to brand ("cauterize"), i.e. (by implication) to render unsensitive (figuratively) -- sear with a hot iron.
see GREEK kaio
STRONGS NT 2743: καυτηριάζωκαυτηριάζω: (καυτήριον ((cf. καίω)) a branding-iron); to mark by branding, to brand: (perfect passive participle) κεκαυτηριάσμενοι τήν ἰδίαν συνείδησιν, i. e. κεκαυτηριασμενην ἔχοντες τήν ἰδίαν συνείδησιν (cf. Winers Grammar, 230 (216)) (cf. ἀκταφθείρω) (branded in their own conscience i. e.) whose souls are branded with the marks of sin, i. e. who carry about with them the perpetual consciousness of sin, 1 Timothy 4:2 R G L, the major edition, see καυστηριάζω; (some (cf. R. V. marginal reading) would give it here the sense of seared, cf. Ephesians 4:19). (In Hippocrates in a medical sense, to cauterize, remove by cautery).)