Mesne Profits

Mesne profits are sums of money paid for the occupation of land to a person with right of immediate occupation, where no permission has been given for that occupation. This situation commonly arises where a landlord has obtained an order from a court for the possession of their land from a tenant who is to be evicted. Some time may elapse from the date of the court order -- which ends the tenancy -- and the recovery of possession by the landlord. The tenant owes no rent for the occupation, since they have ceased to be a tenant, but will be made to pay a charge, usually identical to the rent, which is known as a mesne profit.
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Sum of money claimed by the owner of property against someone not legally entitled to be in possession. Calculated from the date the notice to quit expires until the date possession is given up 

MESNE - The middle between two extremes, that part between the commencement and the end, as it relates to time.

Hence the profits wbich a man receives between disseisin and recovery of lands are called mesne profits. Process which is issued in a suit between the original and final process, is called mesne process.

In England, the word mesne also applies to a dignity: those persons who hold lordships or manors of some superior wbo is called lord paramount, and grant the same to inferior persons, are called mesne lords.

MESNE PROCESS - Any process issued between original and final process; that is, between the original writ and the execution.

MESNE PROFITS - The value of the premises, recovered in ejectment, during the time that the lessor of the plaintiff has been illegally kept out of the possession of his estate by the defendant; such are properly recovered by an action of trespass, quare clausum fregit, after a recovery in ejectment.

As a general rule, the plaintiff is entitled to recover for such time as be can prove the defendant to have been in possession, provided he does not go back beyond six years, for in that case, the defendant may plead the statute of limitations.

The value of improvements made by the defendant, may be set off against a claim for mesne profits, but profits before the demise laid, should be first deducted from the value of the improvements.
   

This entry contains material from Bouvier's Legal Dictionary, a work published in the 1850's.