Perhaps on air one refused a farewell (8)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

SAY (perhaps = for example) + ON A [i] R , refusing the I (one in Roman numerals), then A . Japanese word for “farewell”, used in English as a casual goodbye – though I’ve read that in Japanese it has more the sense of a final I’m-never-going-to-see-you-again.