land, or terra
The word land was normally used with the meaning of arable land; but in some counties, notably in those of circuit 3, it appears to be used in juxtaposition to the word manor, to emphasis the non-manorial status of holdings which rendered their public duties - the payment of taxes and the performance of military service - through another manor. There were also two occurrences in circuit 6, where a marginal T (for terra) was used to emphasise the point.
For divergent interpretations of the significance of this word, see J.H. Round, 'The Domesday manor', English Historical Review, vol. 15 (1900), pages 293-302; John J.N. Palmer, 'The Domesday manor', Domesday studies, edited by J.C. Holt (1987), pages 139-54; and David Roffe, Domesday: the Inquest and the Book (2000).