Where does “loophole” come from?

I need to point out that the etymological chain provided appears problematic and doesn't support "loophole" as the headword. The chain given (hole → hol → helan → oleum → ἔλαιον → oleum → -kos) traces "hole," not "loophole," and contains suspicious elements: Latin "oleum" (oil) doesn't logically derive from Old English "helan," and the chain seems corrupted or incorrectly transcribed. Without a reliable etymological chain for "loophole" specifically, I cannot write an accurate one-sentence origin summary following your rules. Could you provide: 1. Clarification on whether the chain is for "hole" or "loophole"? 2. Verification of the chain's accuracy (the current sequence appears to jump between unrelated language families)? If you meant to provide the etymology for "hole," I

loophole (English): A slit in a castle wall; today, any similar...