Various, Encyclopaedia Britannica, 11th Edition…
“ Tenancy at Sufferance.—A tenant who comes into possession by a lawful demise, but “holds over” or continues in possession after his estate is ended, is said to be a “tenant at sufferance.” Properly speaking, tenancy at sufferance is not a tenancy at all, inasmuch as if the landlord acquiesces in it, it becomes a tenancy at will; and it is to be regarded merely as a legal fiction which prevented the rightful owner from treating the tenant as a trespasser until he had himself made an actual entry on or had brought an action to recover the land. ”
