• Webster's Revised Unabridged Dictionary
    • Knag A knot in wood; a protuberance.
    • Knag A wooden peg for hanging things on.
    • Knag The prong of an antler.
    • Knag The rugged top of a hill.
    • ***
Century Dictionary and Cyclopedia
    • n knag A hook; a peg; a wooden peg for hanging things on.
    • n knag One of the projecting points of a deer's antler; a snag or tine.
    • n knag A protuberant knot; a wart; also, a decorative knot or tuft, as in costume.
    • n knag The rugged top of a rock or hill.
    • ***
Chambers's Twentieth Century Dictionary
    • n Knag nag a knot in wood: a peg
    • ***


Webster's Revised Unabridged Dictionary
Cf. Prov. G. knagge, a knot in wood, Sw. knagg, Dan. knag, a hook to hand clothes on, a bracket; Gael. & Ir. cnag, peg, knob
Chambers's Twentieth Century Dictionary
From a root found in Ir. and Gael. cnag, a knob; cf. Dan. knag, Ger. knagge.


In literature:

You'll not forget my directions, Miss Knag?
"The Life And Adventures Of Nicholas Nickleby" by Charles Dickens
Then you may let it hang on the knag where it is all day.
"The Shepherd's Calendar" by James Hogg