Impudent, a.
Etymology: [L. impudens, -entis; pref. im- not + pudens ashamed, modest, p. pr. of pudere to feel shame: cf. F. impudent.]
Bold, with contempt or disregard; unblushingly forward; impertinent; wanting modesty; shameless; saucy. More than impudent sauciness. Shak. When we behold an angel, not to fear Is to be impudent. Dryden.
Syn. -- Shameless; audacious; brazen; bold-faced; pert; immodest; rude; saucy; impertinent; insolent.
Shades of meaning
Fernald lists impudent only as an antonym, under polite.
Where he writes about it:
Audacity, in the sense here considered, is a reckless defiance of law, decency, public opinion, or personal rights, claims, or views, approaching the meaning of impudence or shamelessness, but always carrying the thought of the personal risk that one disregards in such defiance; the merely impudent or shameless person may take no thought of consequences; the audacious person recognizes and recklessly braves them. — from effrontery
Synonyms
none given