BrownIAN, of course! Here’s an example where, on the contrary, I should have followed logic of Russian – it uses adjective construction, too: БраунОВСКОЕ движение.
Your proposal has classical elegance, but I’m afraid it’s only suited to very short cocktail functions and myriad attendees: for how long can you discuss rains in Spain?
For practicality, can I suggest using Laodicean1 (‘lukewarmish towards religion’) and Laodicean2 (indifferent to politics)?

Churchillianisms: aren’t they also Chandlerianisms
(he preferred to simply call them “wisecracks”, though)?
-You were smart, pal. You fooled me.
-That wouldn’t make me smart.

br549: oh no, no apologies necessary!

I could volunteer to place a foot on each cheek, and a hand on each shoulder, and pry with all my strength, but I doubt that even the world’s strongest man could achieve the desired result.

And …I suspect that talking vividly about the weather may solve the quandary of which topic is best avoided, if you’re entertaining said Laodiceanist …but if they’re a Laodoceanite, I’d probably consider neither topic expressly verboten, but rather “play it by ear” until I’d further plummed the depth of their proclivities.

Virgil: Heh. I did at first italicize “were”, but after rolling it around on my tongue, I decided it would sound better if “her” was emphasized … since Winston was reasonably happily married.

Funny about writing styles, I would have italicized “were”
rather than “her.”

dear, I appreciate your reminding me of another (one of many) inconvenience of English (vs. Russian) : geographical/national descriptive could be read as noun as well as adjective, whilst in Russian these are two distinctly different constructions.

Still, if we are to understand Laodicean‘s primary stress on “lukewarm”, not either of two subjects of said lukewarmness (“politics’ and “religion”), how are we to perceive, which of the two socially prohibitive topics we’re suppose to avoid when attempting to communicate with a self-described Laodician guest?

Churchillian remarks come to my lips much easier in Russian; please consider occasional one in English as pure accident of Brown movement.

If you are an enthusiastic active participant in your politics, the same description would not be appropriate (and would indeed, be entirely inappropriate).

So indeed you could be both wholly Laodicean (a superb pun) and wholly not Laodicean. At the same time. Tho’ as regards different attributes.

…the term’s properly used descriptively as an attribute, not as a noun (well, unless you really are a member of said church/region …in which case we’d be at a bit of a quandary – and sans an otherwise excellent modifier – as to how best to “artistically” describe your unenthusiasm for religion).

In other words, it’s not a gestalt. It’s more of a adjective.

…tho’ the logical extension of the implication of the expression of the sentiment to/about someone as being “half lukewarm” would be an absolutely hilarious and quite witty indictment; Churchillian, actually**. Kudos for that, at least, dear.

**Cf as example Churchill’s response to Nancy Astor when she remarked that if he were her husband she’d give him poison, and Winnie’s retort that if he indeed were her husband, he’d [happily] take it.