A couple of weeks ago Martin McGuinness used a word I hadn't heard before: partitionism.
Southern accents were prevalent amongst customers
I wasn't quite sure what it was, but I had been told it was evil.
Upon consulting The Oxford English Dictionary I found the definition for partition: "Division into parts, especially the division of a country into self-governing parts."
But there is no mention of an "ism".
Some more flicking and I discovered that "ism" is a suffix deriving from the Greek "ismos" and has several potential ways of adding meaning to a noun: 1 denoting an action or its result: baptism. 2 denoting a state or quality: barbarism. 3 denoting a system, principle, or ideological movement: Anglicanism. 4 denoting a basis for prejudice or discrimination: racism. 5 denoting a peculiarity in language: colloquialism. 6 denoting a pathological condition: alcoholism.
So, is partitionism a pathological condition akin to alcoholism? Hello my name is Martin and I'm a partitionist.
Or is it more of an ideological movement such as Anglicanism or Catholicism? This border is the one true border; I shall worship no other boundaries.
Or maybe it is a basis for prejudice like racism? I hate northerners/southerners! (delete as appropriate).
Mr McGuinness used the term in denouncing southern politicians who had criticised citizens of the Republic for shopping in Northern Ireland.
Not only were they wrong, he suggested, but what they were espousing was evil.
In that context, you would have to say his meaning is essentially a combination of the ideology with the prejudice bit, a nasty and discriminatory belief system.
But how widespread is this pernicious philosophy?
It's a question Martin McGuinness may want to consider as he heads for Dublin this weekend with party colleagues for Sinn Fein's Ard Fheis.
Is it confined to the Dublin 4 political class, or do the tentacles of partitionism reach into the four corners of the four provinces?
I had to pay a visit to IKEA the other night. I say "had to" because it's not something I would willingly do.
A good 70% of the accents I heard were southern. Clearly these shoppers were not heeding the call to shop on "their" side of the border.
I'm told the picture is much the same every day of the week.
So, can we assume the general population of the Republic is free of this evil ideology? Not necessarily.
The thing that struck me was that all these southern accents were concentrated in one warehouse in the Belfast Harbour Estate.
The vast majority will probably experience nothing more of Northern Ireland on their visit than a "hello" and "thank you" from the checkout operator.
They are happy with their bargain shopping experience - but they don't really want to linger. They are not defying partitionism - they are embracing it.
On The Politics Show this week we'll be talking to Gerry Adams at the Ard Fheis and we will be asking why Sinn Fein has failed to make any major breakthrough in southern politics. Partitionism, perhaps?
Kevin Sharkey has been investigating and Robin has more on that.
We will have special coverage of the conference live on Saturday on BBC Two at 16.55 GMT, with a half hour round-up on Sunday night at 2300 GMT.
And you can follow the Ard Fheis live on the web here www.bbc.co.uk/ninews from 1100 GMT on Saturday.
PS - "In my view, partition is good, not evil — Northern Ireland has benefited greatly from it. It could also be suggested, however, that partition is something that the Republic of Ireland engaged in when it annexed the Republic from the United Kingdom," First Minister, Peter Robinson in the Assembly recently. Good to see the joint office is working closely together on this.