Our previous house had a catflap in the back door. (We had cats then).
One afternoon my wife, who was born and brought up in the Potteries, called to me in panic, "Dave! Come in here, there's a strug trying to get in through the catflap!"
As I ran into the kitchen I was going through my occult laws, silver bullets for werewolves, garlic for vampires, rowan for witches,... but no information at all about strugs and the threats they might pose.
The 'dreaded strug' at the door was an unfamiliar cat- probably a stray.
So here's another word:- In Staffordshire,
STRUG=stray
Cheers
Dave