broker: [14] Broker has no connection with the past tense of break. It comes from Anglo- Norman brocour ‘small trader’, but its ultimate origin is not clear. A variant Anglo-Norman form abrocour has fuelled speculation as to a link with Spanish alboroque ‘sealing of a bargain’ and Portuguese alborcar ‘barter’, which are presumably of Arabic origin (the alrepresenting the Arabic definite article); but other etymologists have sought to link the word with broach, as if the underlying sense were ‘someone who sells wine from [that is, by broaching] the cask’, and hence any ‘retailer’. [broker etymology, broker origin, 英语词源]