Latin, marca.

The mark of silver was worth 13s 4d, the gold mark £6. The mark was a money of account, not a coin.

For more detail on the coinage, see R.H.M. [Michael] Dolley, The Norman Conquest and the English coinage (1966), and Sally P.J. Harvey, Domesday: Book of Judgement (2013), chapter 6 and appendix 1..