con

American Heritage® Dictionary of the English Language, Fourth Edition

1. adv. In opposition or disagreement; against: debated the issue pro and con.
2. n. An argument or opinion against something.
3. n. One who holds an opposing opinion or view.
4. v. To study, peruse, or examine carefully.
5. v. To learn or commit to memory.
6. v. To direct the steering or course of (a vessel).
7. n. The station or post of the person who steers a vessel.
8. n. The act or process of steering a vessel.
9. v. To swindle (a victim) by first winning his or her confidence; dupe.
10. n. A swindle.
11. adj. Of, relating to, or involving a swindle or fraud: a con artist; a con job.
12. n. Slang A convict.

Century Dictionary and Cyclopedia

1. A dialectal or obsolete variant of can.
2. To try; attempt (to do a thing).
3. To try; examine; test; taste.
4. To peruse carefully and attentively; study or pore over; learn: as, to con a lesson: often with over.
5. Nautical: To direct (the man at the helm of a vessel) how to steer.
6. To give orders for the steering of: as, to con a ship.
7. n. Naut.: The position taken by the person who cons or directs the steering of a vessel.
8. n. The act of conning.
9. n. A variant of can, for gan, preterit of gin, begin. See can, gin.
10. n. An abbreviation of the Latin contra, against (see contra), especially common in the phrase pro and con (Latin pro et contra), for and against, in favor of and opposed to: sometimes used as a noun, with a plural, the pros and cons, the arguments, or arguers, or voters, for and against a proposition.
11. n. The most frequent form of com-.
12. Short for ‘confidence’: as a con man; a con game. See confidence man, confidence game (under confidence).
13. An abbreviation of Consul
14. [lowercase] of conclusion.

Wiktionary

1. n. An organized gathering such as a convention or conference.
2. v. rare To study, especially in order to gain knowledge of.
3. v. rare, archaic To know, understand, acknowledge.
4. v. Variant spelling of conn: to conduct the movements of a ship at sea.
5. n. slang A convicted criminal, a convict.
6. n. A disadvantage of something, especially when contrasted with its advantages (pros).
7. n. slang A fraud; something carried out with the intention of deceiving, usually for personal, often illegal, gain.
8. v. transitive, slang To trick or defraud, usually for personal gain.
9. v. nautical To give the necessary orders to the helmsman to steer a ship in the required direction through a channel etc. (rather than steer a compass direction)
10. n. nautical The navigational direction of a ship

GNU Webster's 1913

1. adv. Against the affirmative side; in opposition; on the negative side; -- The antithesis of pro, and usually in connection with it. See pro.
2. v. obsolete To know; to understand; to acknowledge.
3. v. To study in order to know; to peruse; to learn; to commit to memory; to regard studiously.
4. v. (Naut.) To conduct, or superintend the steering of (a vessel); to watch the course of (a vessel) and direct the helmsman how to steer.

WordNet 3.0

1. v. deprive of by deceit
2. adv. in opposition to a proposition, opinion, etc.
3. n. an argument opposed to a proposal
4. n. a person serving a sentence in a jail or prison
5. v. commit to memory; learn by heart
6. n. a swindle in which you cheat at gambling or persuade a person to buy worthless property