• Webster's Revised Unabridged Dictionary
    • handfast A contract; specifically, an espousal.
    • handfast Custody; power of confining or keeping.
    • a handfast Fast by contract; betrothed by joining hands.
    • handfast Hold; grasp
    • a handfast Strong; steadfast.
    • handfast To betroth by joining hands, in order to permit cohabitation, before the formal celebration of marriage; in some parts of Scotland it was in effect to marry provisionally, permitting cohabitation for a year, after which the marriage could be formalized or dissolved.
    • handfast To pledge; to bind.
    • ***
Century Dictionary and Cyclopedia
    • handfast To take or hold with the hand; hold securely or firmly; grasp.
    • handfast To join together by or as if by the clasping of hands; make fast; bind; specifically, to betroth.
    • handfast In some parts of Scotland, formerly, to marry provisionally by the ceremony of joining hands. Handfasting was a simple contract or agreement under which cohabitation was permitted for a year, at the end of which time the contract could either be dissolved or made permanent by formal marriage. Such marriages, at first probably not intended to be temporary, are supposed to have originated in Scotland from a scarcity of clergy, and have existed at times in other countries.
    • handfast Having a close hand; close-fisted.
    • handfast Bound by pledge, promise, or contract; especially, betrothed, or united as if by betrothal.
    • handfast In Scotland, formerly, joined in provisional wedlock.
    • n handfast Grip; grasp; hold.
    • n handfast Custody; power of confining or keeping; a holding on security or bail.
    • n handfast A pledge, promise, or contract; especially, betrothal.
    • ***
Chambers's Twentieth Century Dictionary
    • Handfast a firm grip, handle: a contract, esp. a betrothal
    • ***


Webster's Revised Unabridged Dictionary
G. handfest,; hand, hand + fest, strong. See Fast
Chambers's Twentieth Century Dictionary
A.S. hand; in all Teut. tongues, perh. rel. to Goth. hinthan, to seize.


In literature:

And anon he made them handfast, and wedded them.
"Le Morte D'Arthur, Volume II (of II)" by Thomas Malory
Heart handfast in heart as they stood, "Look thither," Did he, whisper?
"The Home Book of Verse, Vol. 3 (of 4)" by Various
Indeed, after Euphemia's death, he married his former handfasted wife Elizabeth.
"Notes and Queries, Number 48, Saturday, September 28, 1850" by Various
Handfasting takes place before a marriage is consummated.
"Notes and Queries, Number 51, October 19, 1850" by Various
The 'handfasting' thus concluded, 'Ye hae forgot the bride ale!
"Border Ghost Stories" by Howard Pease
After the handfasting and making of the contract, the church-going and wedding should not be deferred too long.
"Folk-lore of Shakespeare" by Thomas Firminger Thiselton-Dyer
This consisted of "handfasting" and the exchange of something, even if only a kiss, to bind the bargain.
"Women of England, Volume 9 (of 10)" by Burleigh James Bartlett
We are betrothed; and I rejoice at the handfasting.
"The International Monthly, Volume 4, No. 3, October, 1851" by Various
Must love always be handfast to something else?
"Miss Stuart's Legacy" by Flora Annie Steel