['hændˏfɑ:stiŋ;-ˏfæ-]
n.
<古>婚约, 抓牢

handfast \hand"fast`\, v. t. [imp. & p. p. {handfasted}; p. pr.
& vb. n. {handfasting}.]
1. To pledge; to bind. [Obs.]

2. 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.
[Obs.]
[1913 Webster +PJC]

Note: Handfasting was a simple contract of agreement under
which cohabitation was permitted for a year, at the end
of which time the contract could be either dissolved or
made permanent by a 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 to have existed at times in other
countries.
[Century Dict. 1906.]