A tax or toll levied to pay for the cost of defensive town walls, both for their building and repair. The Latin word used in the documents was muragium. It would be imposed on strangers entering the town. However, it was not a permanent tax. To impose murage required a licence from the king in which the length of time it could be collected was specified. [< Lat. murus = a wall] -
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.