barrel knot

:  either of two knots used for tying fishing leaders together: a :  a knot made by twisting the ends of two standing parts one around the other usually two or three times and then pushing the ends back through the center twist —called also blood knot b :  a knot made by tying double or triple overhand knots with each end around the opposite standing part —called also double Englishman's knot, double fisherman's knot, grapevine knot