Fiendish is a related term of impious.
As adjectives the difference between fiendish and impious
is that fiendish is sinister; evil; conniving; in the manner of a fiend while impious is not pious.
fiendish
English
Adjective
(
en adjective)
Sinister; evil; conniving; in the manner of a fiend.
Derived terms
* fiendishly
* fiendishness
Anagrams
* finished
impious
English
Adjective
(
en adjective)
not pious
lacking reverence or respect, especially towards a god