Merriam-Webster's Collegiate® Dictionary, 11th Edition
SNAG
I. noun
Etymology: perhaps of Scandinavian origin; akin to Old Norse snagi clothes peg
Date: circa 1587
1. a tree or branch embedded in a lake or stream bed and constituting a hazard to navigation, a standing dead tree, a rough sharp or jagged projecting part ; protuberance : as, a projecting tooth, one of the secondary branches of an antler, a concealed or unexpected difficulty or obstacle,
4. a jagged tear made by or as if by catching on a snag, an irregularity that suggests the result of tearing, snaggy adjective
II. transitive verb (snagged; snagging)
Date: 1807
1. to catch and usually damage on or as if on a snag, to halt or impede as if by catching on a snag, to hew, trim, or cut roughly or jaggedly, to clear (as a river) of snags, to catch or obtain usually by quick action or good fortune