Historical Dictionary of London

LAD LANE

West from Milk Street to Wood Street, in Cripplegate Ward Within, in continuation of Cateaton Street, now forms part of the present Gresham Street (q.v.).
Earliest mention:"Ladelane," 1301 (Cal. L. Bk. C. p. 238).
Other forms : "Laddelane," 14 Ed. II. 1320 (Cal. P.R. Ed. II. 1317-21, p. 589). "Ladellane," 1361 (Ct. H.W. II. 72). "Laddellane," 1419 (ib. 417). "Lad lane," 1445-6 ib. 507). "Ludlane," 35 H. VIII. 1543 (L. and P. H. VIII. XVIII. Pt. 1, 554). "Lade Lane" otherwise "Ladde Lane," 1561-2 (Ct. H.W. II. 677).
Stow speaks of it as "Ladle lane," or "Ladle hall," corruptly called Lad lane (p. 298), and though the earliest form appears to be "Ladelane," this does not altogether disprove his statement, for the second "l" required to represent the pronunciation "Ladellane" might easily have been slurred over in ordinary speech and omitted by a scribe of the period, to whom the spelling of names often presented serious difficulties. On the other hand, Stow may himself have been in error in suggesting that the second "l" formed an integral part of the name. In either case it is not easy to discover a satisfactory derivation of the name.
Perhaps from A.S. "lad " = "a way, path."
The name Gresham Street superseded the old appellation in 1845.