I just discovered the archaic term ‘Bobadil’ in a Robert Louis Stevenson essay. It apparently derives from Captain Bobadil, a name Ben Jonson used for a braggart in one of his plays.
Obviously there’s some resemblance to Tolkien’s Tom Bombadil in the name and maybe character. I’d guess it likely Tolkien knew the word, but would he have expected his readers to know it? Does anyone know how common ‘Bobadil’ as a word ever was (is it still used today anywhere)?
It’s difficult to get any information from simple internet searches on this one, since even Google thinks I ought to be searching for “Captain Bombadil”.
The question isn’t really whether he expected his readers to know it. Tom Bombadil was originally the name of a stuffed doll his kids had; he would tell them bedtime stories about the doll’s adventures. He was included in Lord of the Rings as a sort of afterthought, at the stage where he still viewed it as a kids’ story, sequel to The Hobbit. While Tolkien’s children were undoubtably more literate and literary than most, it’s unlikely that they would have been familiar with Ben Jonson’s plays at an age where they were hearing bedtime stories about their toys, so no, even if Tolkien was aware of the connection, he would not have expected his audience to be.