Earlier this week the Blether Region passed this van parked outside Willowfield Parish Church on the Woodstock Road. Besom is a Christian organisation in England and Northern Ireland offering help to those in need. Although barely part of Standard English today, the word "besom" appears once in the King James Version of the Bible: "I will sweep it with the besom of destruction, saith the LORD of hosts." — Isaiah 14:23.
In this case, it is tempting to view it also as evidence of how far removed Northern Ireland — or at least the largest and most populous part where the dialect is Mid Ulster English — is from Scotland linguistically. Although Scots is there as a substrate and a source of loan words such as "wee", "dander", etc., only in the Ulster-Scots coastal crescent is it used in its full form. There appear to be no such self-styled Christian "besoms" in Scotland, and no wonder: what sensible woman would want to drive around in a van marked "besom" and prefaced with the name of the local area? She'd be harangued every time she stopped at a red light.
The Scottish National Dictionary defines this figurative use of the word — possibly the most common one in contemporary Scotland and recorded in the Concise Ulster Dictionary too — as "A term of contempt applied to a person, gen. a woman; sometimes to a woman of loose character, sometimes jocularly to a woman or young girl."