Definition of Fee farm
A species of tenure, where land is held of another in perpetuity at a yearly rent, without fealty, homage, or other services than such as are specially comprised in the feoffment. It corresponds very nearly to the "emphyteusis" of the Roman law. Fealty, however, was incident to a holding in fee-farm, according to some authors.
Fee farm is where an estate in fee is granted subject to a rent in fee of at least one-fourth of the value of the lands at the time of its reservation. Such rent appears to be called "fee-farm” because a grant of lands reserving so considerable a rent is indeed only letting lands to farm in fee-simple, instead of the usual method of life or years. Fee-farms are lands held in fee to render for them annually the true value, or more or less; so called because a farm rent is reserved upon a grant in fee. Such estates are estates of inheritance. They are classed among estates in fee-simple. No reversionary interest remains in the lessor, and they are therefore subject to the operation of the legal principles which forbid restraints upon alienation in all cases where no feudal relation exists between grantor and grantee.
That's the definition of Fee farm in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.