The granny knot is a binding knot, used to secure a rope or line around an object. It is considered inferior to the reef knot (square knot), which it superficially resembles. Neither of these knots should be used as a bend knot for attaching two ropes together. When attempting to tie a reef knot, it is easy to produce a granny knot accidentally. T...[mathematics] In knot theory, the granny knot is a composite knot obtained by taking the connected sum of two identical trefoil knots. It is closely related to the square knot, which can also be described as a connected sum of two trefoils. Because the trefoil knot is the simplest nontrivial knot, the granny knot and the square knot are the...
(from the article `knot theory`) ...highest known by the end of the 20th century. Certain higher-order knots can be resolved into combinations, called products, of lower-order knots; ...
A double knot in which the free ends of the second loop are asymmetric and not in the same plane as the free ends of the first loop. ... (05 Mar 2000) ... 
an incorrectly tied reef knot
Type: Term Definitions: 1. a double knot consisting of two asymmetric half hitches, which tends to slip under tension.
[n] - a reef knot crossed the wrong way and therefore insecure
granny noun a reef knot crossed the wrong way and therefore insecure