In an urban context, and specifically the late 19th and early 20th century industrial and shipbuilding towns, a land is exactly what would be called a tenement or a block of flats these days. Usually with a single entrance close and a stair or stairs giving access to one or more flats/apartments/dwellings on each floor. The name might be that of the owner, from whom all the occupants rented their homes, or it might be the name of a prominent or important citizen who lived in it. This does mean that in some cases, even though the actual building is still in existence, its name may have changed.
The word 'tenement' has undergone change; in the 18th and early 19th century it also meant a small, usually rented, piece of ground. So, for instance, during the Enlightenment between 1750 and 1850, when it was fashionable for landowners to establish new planned towns to replace the huddled old villages, the ground for the new town or village would be divided into tenements and then rented to the tenants. Some landowners might build houses on each tenement; more often they would simply rent the tenements and expect the tenants (or tenementers) to build their own houses on their tenements. In many cases the landlord specified the sort of house that was to be built, for example they might specify that it was to be 2 storeys high, and with its long elevation on the street frontage.
In towns and cities there was obviously much more demand for housing, so what would be called a tenement now is a development of this idea, where the building on a tenement was much larger and intended to accommodate many households, not just one as in more rural tenements. A tenement building did not need to be umpteen storeys high - it might only be a ground floor and say two storeys in places where the pressure on building space was less intense than in the big cities.
The lands in Edinburgh (and several other towns and cities) are a stage further than the more general land because not only are there tenements built on the street frontages, but what would originally have been garden ground in the closes behind has all been built up, so that the close doesn't give access to one tenement, but also to several more tenement buildings and houses built on the original tenement of ground.
The (former) village of Duntocher is indeed a couple of from the (former) village of Old Kilpatrick (if you can really call either of them villages these days) but both are in the parish of Old Kilpatrick. So 'Duntocher in the parish of Old Kilpatrick' is an exact and 100% correct description. New Kilpatrick is the next parish to the east.
The parish boundaries have little or no relevance these days, but they are very important for finding older records, because these were arranged by parish. According to Fullarton's Gazetteer (1842) Old or West Kilpatrick is "bounded on the north by Stirlingshire; on the east by East Kilpatrick and Lanarkshire; on the south or south-west by the Clyde, which divides it from Renfrewshire; and on the north-west by the parish of Dumbarton". East or New Kilpatrick is "partly in Dumbartonshire and partly in Stirlingshire; bounded on the north by Killearn and Strathblane; on the east by Strathblane and Baldernock; on the south by Lanarkshire and Renfrewshire; and on the west by Old Kilpatrick".