Lode

google

ref

Old English lād ‘way, course’, variant of load. The term denoted a watercourse in late Middle English and a lodestone in the early 16th century The current sense dates from the early 17th century.

wiktionary

ref

Doublet of  load, which has however become semantically restricted. The now-archaic lode continues the old sense of Old English lād(“way, course, journey”) but by the 19th century survived only dialectally in the sense of “watercourse”, as a technical term in mining, and in the compounds  lodestone,  lodestar. 

etymonline

ref

lode (n.)

Middle English spelling of load (n.) "a burden," it keeps most of the word's original meaning "a way, a course, something to be followed." The differentiation in sense took place 16c., that of spelling somewhat later. Mining sense of "vein of metal ore" is from c. 1600, from the notion of miners "following" it through the rock. Also found in lodestone, lodestar, and, somewhat disguised, livelihood. Middle English also had lodesman (c. 1300) "leader, guide; pilot, steersman."