To walk in Pimlico. To promenade, handsomely dressed, along Pimlico Path.
“Not far from this place were the Asparagus Gardens and Pimlico Path, where were fine walks, cool arbours, etc., much used by the citizens of London and their families.” —Nat. Hist. Surrey, v. 221.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894