Definition of handfasted:
(v) :
(transitive) To pledge; to bind.
(v) :
(transitive, Scotland, archaic or historical except Wicca) To betroth by joining hands, in order to allow for cohabitation before the celebration of marriage; to marry provisionally.
(n) :
(obsolete) A contract, agreement, covenant; specifically betrothal, espousal.
(adj) :
(obsolete) Fast by contract; betrothed by joining hands.
(n) :
(obsolete) A hold, grasp; custody, power of confining or keeping.
(adj) :
(rare) Strong; steadfast.