n. & v.
n. 1 a metal loop or link, closed by a bolt, to connect chains etc. 2 a fetter enclosing the ankle or wrist. 3 (usu. in pl.) a restraint or impediment.
v.tr. fetter, impede, restrain. shackle-bolt 1 a bolt for closing a shackle. 2 a bolt with a shackle at its end.
[ OE sc(e)acul fetter, corresp. to LG shkel link, coupling, ON skökull wagon-pole f. Gmc ]