hub: [17] Hub is one of those words that emerge unheralded from the undergrowth of language, its forbears uncertain. It seems originally to have meant ‘lump’, and is probably ultimately the same word as hob [16]. This was at first spelled hub and may have denoted a lump of clay used as a bakestone, or a brick or clay projection at the back of a fire on which things were placed to keep warm. And hobnail [16] is etymologically a nail with a large ‘lumpy’ head. => hob[hub etymology, hub origin, 英语词源]