Easton's Bible Dictionary: M. G. Easton, M.A., D.D.

Coos

(written Cos in the R.V.), a small island, one of the Sporades in the Aegean Sea, in the north-west of Rhodes, off the coast of Caria. Paul on his return from his third missionary journey, passed the night here after sailing from Miletus (Acts 21:1). It is now called Stanchio.