Definition of snag:
(n) :
a
stump or base of a branch that has been lopped off; a short branch, or a sharp or rough branch; a
knot; a
protuberance; a
tooth projecting beyond the rest; contemptuously, a broken or decayed tooth
(v) :
to
catch or
tear (e.g. fabric) upon a rough surface or projection; to
fish by means of dragging a large
hook or hooks on a
line, intending to
impale the body (rather than the mouth) of the target
"be careful not to snag your stockings on that concrete bench!"