UNCHRISTIAN
unchristian
(adjective) not of a Christian faith
Source: WordNet® 3.1
Etymology
Adjective
unchristian (comparative more unchristian, superlative most unchristian)
Not of the Christian faith.
Not in accord with Christian principles; without Christian spirit; unbefitting a Christian.
Source: Wiktionary
Un*chris"tian, a. Etym: [Pref. un- not + Christian.]
1. Not Christian; not converted to the Christian faith; infidel.
2. Contrary to Christianity; not like or becoming a Christian; as,
unchristian conduct.
Un*chris"tian, v. t. Etym: [1st pref. un- + Christian.]
Definition: To make unchristian. [Obs.] South.
Source: Webster’s Unabridged Dictionary 1913 Edition