There is a nice link to Robert Burns Vocabulary that Margo contributed to another thread here. This link has been very helpful for me in understanding some of the words in Scottish tunes. I quickly saw that lo'ed means loved. Here's the link. click here...and thanks again, Margo.
Also, Lesley Nelson has some great info on Child #214, Rare Willie (one of my favorites) at her site. There are also links to maps and the Yarrow River, etc.
Mary