A unit for measuring the depth of water. The fathom is commonly viewed as being four cubits (c. 1.8 m; 6 ft) and approximately corresponds to the distance between the fingertips of a man’s two hands when his arms are stretched in opposite directions. Appropriately, the Greek word for “fathom” (or·gui·aʹ) comes from a root meaning “stretch out; reach.”​—Ac 27:28, ftn.