Q:

How to say *heathenous?

I want to decry an act or object as having heathen-like qualities. I would call it *heathenous, except apparently this word is neither in the dictionaries nor oft-seen by google.

A:

Depending on the context in which you intend to use it, there are a few options:

heathen: this is also an adjective, so it would seem the most obvious choice
pagan: denotes non-Christian or pre-Christian, with no strong positive or negative connotation per se; in modern times also of a spiritualist movement
unchristian: has a negative connotation: lacking all traditional Christian virtues, especially charity
heretical: denotes being antagonistic to standard thinking
barbarous: connotes cruelty and crudeness
barbaric: connotes being primitive, especially as regards gaudy decoration
barbarian: most neutral word for being uncivilised

A:

Simply use "heathen".

These heathen rites will bring down the wrath of the Flying Spaghetti Monster on our heads.

This doesn't work so well as a predicate, adjective, however. In that context, there is no derivative of heathen that will work, so I'd go with pagan.

? This belief is heathen. [Sounds very odd.]
This belief is pagan. [Sounds fine, means almost the same thing.]

