ˈimpēəs, (ˈ)im|pīəs adjective
Etymology: Latin impius, from in- in- (I) + pius pious — more at pious
: not pious : irreverent:
a. : lacking reverence for God, a deity, or for what is sacred : profane , irreligious
an impious life
b. : lacking in proper respect (as for parents or for something usually held in general respect)
an impious son
an impious flouting of experience — Donagh MacDonagh
any alteration in the ceremonies that surrounded Thanksgiving would have been considered impious and heartbreaking by my mother — John Cheever
Synonyms:
profane , blasphemous , sacrilegious : impious usually implies extreme disrespect for a divinity or his attributes and manifestations
the impious challenge of power divine — William Cowper
who is there more impious than a backsliding priest? — John Steinbeck
profane in this sense may suggest not only the disrespect involved in impious but also desecration, intentional or not, of something to be held inviolate
hitherto no liberal statesman has been so audacious as to “imagine the king's death” and lay profane hands on the divine right of nations to seek their own advantage at the cost of the rest by such means as the rule of reason shall decide to be permissible — Thorstein Veblen
I collected bones from charnel houses; and disturbed, with profane fingers, the tremendous secrets of the human frame — Mary W. Shelley
blasphemous may apply to strong and intentional impiety or profanation fervently expressed or performed or to the harboring and abetting of ideas calculated to lower the awesome dignity of a deity
blasphemous conversation
it is blasphemous because it attributes to God purposes which we would not respect even in an earthly parent — J.A.Pike
sacrilegious commonly may describe any flagrant depredation, disrespect, or contempt
sacrilegious in his scandalous burlesques of the gods
All of these words lend themselves to broad and inexact uses.