The Oxford Dictionary of English Surnames says:
Lean / Leane:
Hugo Macer 1208 (Oxfordshire);
Walter Lene 1276 (Yorkshire);
John Leane 1317. Old English hlæne "lean, thin" (Latin "macer"). Also from MacLean.
MacLean / Maccleane / Maclaine / Maclane:
Lachlan M'Gilleon 1436,
Alexander McKlane 1648. Gealic Mac Gille
Eoin "Son of the servant of St.
John"
I thought this might be of interest.
Andy;—)