Round turn

From WikiPOBia

Specifically, a round turn is the passing of a line through 360 degrees around an object. The friction caused by the turn when such a line comes under tension is dramatic. Thus, in tending a line apt to become under tension, a sailor will often "catch a turn" around a belaying pin, cleat, or bit to aid him should the lien come under heavy strain.

A common example is, "a round turn and two half-hitches", a knot said to be "Good enough for the King's yacht"

Characters throughout the canon frequently speak of being, "brought up with a round turn".