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Sear
SEAR [ISBE]
SEAR - ser: In 1 Tim 4:2 for (kausteriazo), "burn with a hot iron" (compare "cauterize"), the King James Version "having their conscience seared with a hot iron," and the Revised Version margin. "Seared" in this connection means "made insensible," like the surface of a deep burn after healing. The verb, however, probably means "brand" (so the Revised Version (British and American)). "Criminals are branded on their forehead, so that all men may know their infamy. The consciences of certain men are branded just as truly, so that there is an inward consciousness of hypocrisy." See the commentaries
Also see definition of "Sear" in Word Study