quitter

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. One who gives up easily.

Century Dictionary and Cyclopedia

1. n. One who quits.
2. n. A deliverer.
3. n. Matter flowing from a sore or wound.
4. n. In farriery, a fistulous wound upon the quarters or the heel of the coronet, caused by treads, pricks in shoeing, corns, or other injuries which produce suppuration at the coronet or within the foot.
5. n. Scoria of tin.
6. To suppurate.
7. n. One who quits or gives up in the face of difficulties; one who has not the courage or determination to finish what he undertakes to do.
8. n. Specifically, a workman who has the habit of throwing up his job on slight pretenses.
9. n. A young male fur-seal, old enough to enter the breeding grounds toward the close of the season, but not strong enough and bold enough to hold his ground when disturbed: he therefore quits his place.

Wiktionary

1. n. Jamaica Matter flowing from a wound or sore; pus.
2. n. A fistulous wound at the top of a horse's foot resulting from bruises, pricks, or neglected corns.
3. n. obsolete Scoria of tin.
4. v. To suppurate; ooze with pus.
5. n. One who quits.
6. n. obsolete A deliverer.

GNU Webster's 1913

1. n. One who quits.
2. n. obsolete A deliverer.

WordNet 3.0

1. n. a person who gives up too easily