Webster's Revised Unabridged Dictionary · 1913

Shameless

Shameless , adjective

[Anglo-Saxon scamleás.]

1.
Destitute of shame; wanting modesty; brazen-faced; insensible to disgrace.
Such shameless bards we have. — Pope
Shame enough to shame thee, wert thou not shameless. — Shakespeare
2.
Indicating want of modesty, or sensibility to disgrace; indecent; as, a shameless picture or poem.