From Old English streng 'cord,' from PIE *strenk- 'tight' — the same root behind strong and stringent.
A thin piece of cord, twine, or similar material used for tying or fastening.
From Old English streng 'cord, rope, bowstring,' from Proto-Germanic *strangiz 'string, cord,' from PIE *strenk- 'tight, narrow.' The musical instrument sense developed from bowstrings being plucked for sound; the computing sense dates to 1956. Key roots: *strenk- (Proto-Indo-European: "tight, narrow").