Where does “ora” come from?

I need to work backwards through this chain to construct an accurate etymology sentence for "ora." However, I notice the chain provided seems disconnected from a headword "ora" - the chain shows "os," "o," "oh" and various Proto-Indo-European roots, but doesn't clearly trace back to "ora" specifically. Let me reconsider: if this chain is meant to show the etymology of "ora," I need to identify which of these elements connect to it. The chain shows multiple branches that don't obviously converge on "ora." Given the constraint that I can "state only what the chain supports" and should "not invent," and given that the chain provided doesn't clearly support an etymology for "ora" back to the stated PIE roots, I cannot in good faith construct a sentence. Could you clarify: 1. Whether "ora" is the correct headword for this chain? 2. Whether there are

ora (English): plural of os; mouths or openings, especially of...