Real Dictionary

string
A string of places or objects is a number of them that form a line.
A string of similar events is a series of them that happen one after the other.
countable noun: A string of things is a number of them on a piece of string, thread, or wire.
countable noun: The strings on a musical instrument such as a violin or guitar are the thin pieces of wire or nylon stretched across it that make sounds when the instrument is played.
variable noun: String is thin rope made of twisted threads, used for tying things together or tying up parcels.

string in American English
a thin line of twisted fiber used for tying, pulling, fastening, etc.; slender cord or thick thread
noun: a slender cord or thick thread used for binding or tying; line

string in British English
noun: a thin length of cord, twine, fibre, or similar material used for tying, hanging, binding, etc