handfast
adjective
1. (obsolete) Fast by contract; betrothed by joining hands.
2. (rare) Strong; steadfast.
noun
1. (obsolete) A hold, grasp; custody, power of confining or keeping.
2. (obsolete) A contract, agreement, covenant; specifically betrothal, espousal.
verb
1. (transitive) To pledge; to bind
2. (transitive, Wicca) To betroth by joining hands, in order to allow cohabitation before the celebration of marriage; to marry provisionally.