Lacking shame, destitute of feelings of modesty; impudent, audacious, immodest; insensible to disgrace.

having a hard skin or outer coat; (also figurative) = thick-skinned, adj. 2.

past shame, dead to shame, no longer capable of feeling shame, grown callous to shame.

Not blushing or reddening.

shameless.

figurative. Dull of sensation or feeling; obtuse, stolid; now esp. not sensitive to criticism or rebuff; the opposite of thin-skinned.

past shame, dead to shame, no longer capable of feeling shame, grown callous to shame.

Of a person, the conscience, etc.: that has become callous, inured, or indifferent; (of an action or attitude) characteristic of such a person…

(un-, prefix1 affix 1b.)

figurative. Hardened, insensitive, callous; not easily moved.

figurative. Thick-skinned; not sensitive to rebuff, ridicule, or abuse; not easily affected by outside influences.

Of a person: hard-headed, shrewd, esp. in a ruthless, unsentimental manner; hardened, callous; tough and cynical. Also of a place: full of or…

figurative. Insensitive to attack; thick-skinned; unfeeling.

In the philosophy of William James: marked by a purely empirical, sceptical, non-metaphysical approach to questions; opposed to tender-minded, adj.…

With bowels of bronze, tough.