Meaning

noun an excavation; usually a quarry or mine

originFrom Middle English delf, delve, dælf (“a quarry, clay pit, hole; an artificial watercourse, a canal, a ditch, a trench; a grave; a pitfall”), from Old English delf, ġedelf (“delving, digging”) and dælf (“that which is dug, delf, ditch”), from Proto-West Germanic *delban (“to dig”), from Proto-Germanic *delbaną (“to dig”). More at delve.

Etymology from Wiktionary, CC BY-SA 3.0