Safety chain.
(a) (Railroads)
A normally slack chain for preventing excessive movement between a truck and a car body in sluing.
(b)
An auxiliary watch chain, secured to the clothes, usually out of sight, to prevent stealing of the watch.
(c)
A chain of sheet metal links with an elongated hole through each broad end, made up by doubling the first link on itself, slipping the next link through and doubling, and so on.
© Webster 1913