Green’s Dictionary of Slang

con n.1

[abbr.]

1. [early 19C] a confidant.

2. [mid-19C–1910s] a conundrum.

3. [late 19C] a contract.

4. [late 19C–1910s] a conformist.

5. [late 19C+] a railroad conductor.

6. [late 19C+] a confidence man.

7. [late 19C+] a confidence game or trick; by ext., deceitful talk.

8. [late 19C+] a convict; thus ex-con n.; occas. attrib.

9. [1900s–50s] a deceptive speech.

10. [1900s] (US) consumption (tuberculosis).

11. [1920s+] a conviction.

12. [1940s] confidence.

13. [2010s] consignment.

In compounds

con-artist (n.)

see separate entry.

con boss (n.) (also boss con) [boss n.2 (1)]

[1910s+] (US prison) an influential convict who runs a gang within a prison.

con game (n.) [game n. (6)]

[late 19C+] (orig. US) a piece of confidence trickery.

con job (n.)

see separate entry.

con-man (n.)

see separate entry.

con-merchant (n.) [merchant n.]

[1930s+] (US) a confidence trickster.

con-mob (n.)

[1930s–40s] (US Und.) a team of confidence tricksters.

con talk (n.)

[late 19C–1900s] (US) insincerity, lies.

conwise (adj.) [-wise sfx (1)] [1910s+] (US prison)

1. well-adjusted to prison life, capable of sustaining one’s existence in prison; of officers, experienced.

2. manipulative of the system.

con work (n.)

[1920s] (US) insincerity, lies.

In phrases

big con (n.)

[1940s+] (orig. US Und.) any major confidence trick, the keynote of which is that the victim is persuaded to send for (usu. large sums of) money, rather than merely defrauding them of what they may have in their possession.

on the con

[20C+] working as a confidence trickster.

play con (v.)

[1960s–70s] to trick, to hoax, to practice confidence trickery.

play the con (v.) (also play con)

[1940s+] (orig. US Und.) to pretend, to attempt to swindle or deceive.

slow con (n.)

[20C+] a fraudulent scheme or confidence trick in which the victim is nurtured slowly and carefully towards their downfall.

soft con (n.)

[1970s] flattery, persuasion, any form of deceit based on soft words.

solid con (n.) [solid adj. (3) ]

[20C+] (US Und.) a trustworthy fellow criminal or prison inmate.

sweet con (n.)

[1950s] (US) a form of begging in which the beggar uses persuasion and promises rather than threats.