I'd like to know just so I can have a character shout out in anger, "Antidisestablishmentarianism doesn't work that way!"

Hm.

Antidisestablishmentarianism—

Anti: The opposite of

Dis: The absence or opposite of.

(Double negative = excess wording)

Establishment: See here.

Arianism: Arianism is the theological teaching attributed to Arius, a Christian Presbyterian from Alexandria, Egypt, concerning the relationship of the entities of the Trinity ('God the Father', 'God the Son' and 'God the Holy Spirit') and the precise nature of the Son of God.

So. Establishment of Arianism, I take it.

From The Other Wiki: Antidisestablishmentarianism is a political position that originated in 19th-century Britain in opposition to proposals for the disestablishment of the Church of England, that is, to remove the Anglican Church's status as the state church of England, Ireland, and Wales.

"Establishment" refers to making the Church of England the official state religion of the UK, with the king or queen as the head of the Church.

"Disestablishment" would reverse this.

"Antidisestabliahment" is being against that reversal.

"-arian" is a referential suffix like libertarian, agrigarian or even libtarian.

And "-ism" of course refers to a viewpoint or ideology.

So antidisestablishmentarianism is the ideology held by people opposed to removing the Church of England as the official state religion of the UK.

http://www.onelook.com/?w=antidisestablishmentarianism&ls=a

For some reason I had gotten the impression that the movement was in Ireland, but apparently it's just that the Disestablishmentarian position won there, disestablishing the Church of England from the position of fficial church in Ireland.

The more you know.

It might be reasonable to generalize the term to refer to anyone who opposes separating church and state in a society that has an established church.

Or perhaps it's not reasonable to do so, and antidisestablishmentarianism doesn't work that way.