By the way, although I know aldi and some others here are fans of the site, this seems like a good time to point out why I don’t think much of Etymology Online.
1) All they do is crib from other references, mostly but not always reliable.
2) Even when they crib from a reliable source (such as the OED, in this example) they sometimes muddle the information. (We’ve seen other examples besides the current one, though I couldn’t recite them off the top of my head.)
3) How much trust can you put in etymologies from people who don’t know a ν (nu) from an υ (upsilon), and write things like apheliou?
I can understand that second-hand, occasionally muddled etymologies are better than no etymologies at all, but given that AHD is free online, I can’t see much reason to cite etymonline.