(n.) The fourth wheel of a supermarket trolley which looks identical to the other three but renders the trolley completely uncontrollable.
I was caught out by the motspur on my trolley and knocked over a baked beans pyramid at the shops yesterday.
by MrSplinch December 16, 2016
The wheel on a shopping cart that looks totally normal.....but when the trolley is loaded makes the whole thing uncontrollable.
by Paul December 25, 2003
by McGluey July 31, 2008