Definition of the word close in

The phrase "close in" is a nautical term that means approaching the shore or harbor. In seafaring language, a ship is said to be "close in" when it is near the coast or shoreline. This term is used to indicate that the vessel is moving inwards from the open sea towards a specific destination. The phrase originally came from the need for ships to navigate close to the shore in order to avoid dangerous reefs, rocks, and other obstacles that lay hidden beneath the surface of the water. In modern usage, "close in" can also be used metaphorically to describe approaching a particular goal or situation with intensity and focus, as if one is maneuvering towards a specific destination through a complex or challenging environment.