attorn

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb To recognize or bring about a transfer, especially of property.
• intransitive verb To transfer (something) to another.

from The Century Dictionary.

• To turn over to another; transfer; assign.
• In old English law, to turn or transfer, as homage or service, to a new possessor, and accept tenancy under him.
• In feudal law, to turn or transfer homage and service from one lord to another.
• In modern law, to acknowledge being the tenant of one who was not the landlord originally, but claims to have become such.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb (Feudal Law) To turn, or transfer homage and service, from one lord to another. This is the act of feudatories, vassals, or tenants, upon the alienation of the estate.
• intransitive verb (Modern Law) To agree to become tenant to one to whom reversion has been granted.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb intransitive, law To transfer one's obligations to a person to another person.
• verb intransitive, law To consent to the transfer of one's obligations as tenant under a lease to a new landlord.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb acknowledge a new land owner as one's landlord