Daniel Cassidy, in his idiotic pretend piece of ‘research’ How The Irish Invented Slang, claimed that ‘to root for someone’, a 19th century American slang term now found in English all over the world, derives from the Irish word radadh, or perhaps the Scottish Gaelic rabhd. These are two different words in two different languages, so it is hard to see what Cassidy is actually saying here.
I don’t intend to go into too much detail about rabhd. I imagine it is probably a loanword from a Scots term related to rout, which we will discuss below. And as for radadh, this has an obsolete literary meaning of bestow, or it means to fling things, to kick (especially of animals) or to frolic or gambol, an extension of the kick meaning. I have heard the expression ag radadh maslaí (hurling abuse) but I can’t see any of these meanings giving rise to a use like ‘we’re rooting for our team’.
And then again, there is a pretty good candidate in English (or Scots). Cassidy chose to ignore this candidate and pretend that it doesn’t exist (or perhaps he was just too lazy to look it up in the dictionaries.) The Great Fraud says that “all Anglo-American dictionaries derive the loud Irish-American root of the ballpark from the English root of a pig rooting in the muck with its nose.”
Which is strange, because Collins’ Dictionary says that it is a variant of Scottish rout, to make a loud noise, from Old Norse rauta (I don’t know for a fact, but I imagine this is the origin of radhd in Gaelic.) And Merriam-Webster also derives root from rout.
And that just goes to show that you really can’t trust a word that Daniel Cassidy wrote. The man was a pathological liar.