Read the dictionary definition of con. All definitions for this word.
1. a swindle in which you cheat at gambling or persuade a person to buy worthless property
2. an argument opposed to a proposal
3. a person serving a sentence in a jail or prison
4. commit to memory; learn by heart
1. Have you memorized your lines for the play yet?
5. deprive of by deceit
1. He swindled me out of my inheritance
2. She defrauded the customers who trusted her
6. in opposition to a proposition, opinion, etc.
1. much was written pro and con
See also: Merriam-Webster definition of con