a series of linked metal rings used for fastening or securing something, or for pulling loads

he slid the bolts on the front door and put the safety chain across

the drug dealer is being kept in chains

a sequence of items of the same type forming a line

he kept the chain of buckets supplied with water

a jointed measuring line consisting of linked metal rods

a structure of planks projecting horizontally from a sailing ship's sides abreast of the masts, used to widen the basis for the shrouds

fasten or secure with a chain

she chained her bicycle to the railings