Also see definition of "Fetter" in Word Study
Fetter
FETTER [isbe]
FETTER - fet'-er: Found only in the plural in both Old Testament and New Testament; fetters of iron (Ps 105:18; 149:8; so probably Mk 5:4; Lk 8:29) or brass (Jdg 16:21; 2 Ki 25:7) were frequently used for securing prisoners.See CHAIN.
Figurative: of trouble (Job 36:8).
Also see definition of "Fetter" in Word Study