Chelsea tractor
n.— «About half the mums round this way use (not drive!) Chelsea Tractors on the brat run. The only time that they ever get to go off road is when they park on the grass verges to *avoid* the double yellow lines or zig-zags.» —“Re: Listen…“ by Robert Bird Usenet: demon.local Sept. 14, 1997. (source: Double-Tongued Dictionary)