The maximum landing weight (MLW) is the maximum aircraft gross weight due to design or operational limitations at which an aircraft is permitted to land.
The operation landing weight may be limited to a weight lower than the maximum landing weight by the most restrictive of the following requirements:
If the flight has been of short duration (for example an emergency just after takeoff), it may be necessary to dump fuel to reduce the landing weight.
Where aircraft overweight landing is permitted, a structural inspection or evaluation of the touch-down loads before the next aircraft operation will be required in case damage has occurred.
References
Maximum landing weight Wikipedia(Text) CC BY-SA