duffer

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An incompetent or dull-witted person.
• noun A casual or mediocre player of a sport, especially golf.
• noun Slang A peddler of cheap merchandise.
• noun Slang Something worthless or useless.

from The Century Dictionary.

• noun A stupid, dull, plodding person; a fogy; a person who only seemingly discharges the functions of his position; a dawdling, useless character: as, the board consists entirely of old duffers.
• noun A peddler; specifically, one who sells women's clothes.
• noun A hawker of eheap, flashy, and professedly smuggled articles; a hawker of sham jewelry.

from the GNU version of the Collaborative International Dictionary of English.

• noun Slang, Eng. A peddler or hawker, especially of cheap, flashy articles, as sham jewelry; hence, a sham or cheat.
• noun Slang A stupid, awkward, inefficient person.
• noun (Mining) See shicer.
• noun (Zoöl.) Any common domestic pigeon.
• noun Australia One who duffs cattle, etc.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective comparative form of duff: more duff
• noun informal An incompetent or clumsy person.
• noun sports A player having little skill, especially a golfer who duffs.
• noun archaic A pedlar or hawker, especially one selling cheap or substandard goods.
• noun archaic Cheap or substandard goods sold by a duffer.
• noun A cow that does not produce milk.
• noun Australia, dated A cattle thief; one who alters the brands of cattle.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an incompetent or clumsy person