Luke 5:4

Launch out. Rev., put out. The singular number, addressed to Peter as master of the craft.

Let down [χ α λ α σ α τ ε]. The plural, addressed to the whole of the boat's crew. Originally, to slacken or loosen, as a bow - string or the reins of horses; hence to let sink as a net. Also of unbarring a door. Metaphorically, to be indulgent, to pardon. The word occurs in the New Testament seven times, and five of these in Luke. He uses it of letting down Paul in a basket at Damascus (Acts 9:25); of striking a ship's sails, and of letting down a boat into the sea (Acts 27:17; Acts 27:30). Matthew, Mark, and John use ballw or ajmfiballw, for casting a net (Matthew 4:18; Matthew 13:47; Mark 1:16; John 21:6), which appears also in the compound noun for a casting net (amfiblhstron, see on Matthew 4:18). The word used by Luke was in common use in medical writings, to denote relaxation of the limbs; loosening of bandages; abatement of sickness; letting herbs down into a vessel to be steeped.