Definition of knags:
(n) :
A peg or hook for hanging something on
(n) :
A short spur or stiff projection from the trunk or branch of a tree, such as the stunted dead branch of a fir
(n) :
A knot in a piece of wood or the base of a branch
(n) :
A pointed rock or crag
(n) :
(Scotland) A small cask or barrel; a keg or noggin
(v) :
To hang something on a peg