Handcuff, n. — Webster enters it under “handcuff”
Etymology: [AS. handcops; hand hand + cosp, cops, fetter. The second part was confused with E. cuffs,]
A fastening, consisting of an iron ring around the wrist, usually connected by a chain with one on the other wrist; a manacle; -- usually in the plural.
1 other Webster entry under this spelling
Handcuff, v. t. [imp. & p. p. Handcuffed; p. pr. & vb. n. Handcuffing.]
To apply handcuffs to; to manacle. Hay (1754).
Shades of meaning
Fernald has no entry of its own for handcuffs; he lists it under fetter.
Where he writes about it:
Manacles and handcuffs are for the hands, fetters are primarily chains or jointed iron fastenings for the feet; gyves may be for either. — from fetter
Gyves is now wholly poetic, and the other words are mostly restricted to the literary style; handcuffs is the specific and irons the general term in popular usage; as, the prisoner was put in irons. — from fetter