I try to put a mixture of modern slang and old slang into Jo's dialogue because I like it. So I thought, I'd share one site I use for it, incase any of ya wants to know or use it yourself.
A Guild To 1920's to 1940's Phrases & Slang
All Wet - Describes an erroneous idea or individual, as in, "he's all wet."
Applesauce - an explative; same as horsefeathers, As in "Ah applesauce!"
Big Cheese - The most important or influential person; boss. Same as big shot.
Bluenose - An excessively puritanical person, a prude, Creator of "the Blue Nozzle Curse."
Broad- Woman, Dame
Bump Off - To murder, To kill.
Carry a Torch - To have a crush on someone.
Cat's Meow - Something splendid or stylish; The best or greatest, wonderful.
Darb - An excellent person or thing (as in "the Darb" - a person with money who can be relied on to pay the check).
Dame- A Woman
Drugstore Cowboy - a guy that hangs around on a street corner trying to pick up girls.
Dumb Dora - a stupid female.
Fall Guy - Victim of a frame.
Flat Tire - A dull witted, insipid, disappointing date. Same as pill, pickle, drag, rag, oilcan.
Frame - To give false evidence, to set up someone.
Gams - A woman's legs.
Giggle Water - An intoxicating beverage; alcohol.
Gin Mill - An establishment where hard liquor is sold; bar.
Hard Boiled - a tough, strong guy.
Heebie-Jeebies - The jitters.
High-Hat - To snub.
Hooch - Bootleg liquor
Hoofer - Dancer.
Horsefeathers - an explative; same usage as applesauce.
Hotsy-Totsy - Pleasing.
Jalopy - Old car.
Joint - A club, usually selling alcohol.
Keen - Attractive or appealing.
Kisser - Mouth.
Line - Insincere flattery.
Lounge Lizard - a horny dog.
Moll - A gangster's girl.
Ossified - a drunk person.
Pinch - To arrest.
Pushover - A person easily convinced or seduced.
Ritzy - Elegant (from the hotel).
Scram - Ask someone to leave immediately.
Sheba - A woman with sex appeal (from the move Queen of Sheba) or (e.g. Clara Bow).
Sheik - A man with sex appeal (from the Valentino movies)
Soitently- Sure!
Speakeasy - An illicit bar selling bootleg liquor.
Spiffy - An elegant appearance.
Spread Out!- Get out of the way! Give me some room! Stop crowding me!
Stuck On - Having a crush on.
Swanky - Ritzy.
Swell- Wonderful.
Take for a Ride -
Upchuck - To vomit when one has drunk too much.
Wise guy- A Smart Ass
Whoopee - To have a good time.
http://www.angelfire.com/comics/howardfineandhoward/20sTo40sPhrases.html
A Guild To 1920's to 1940's Phrases & Slang
All Wet - Describes an erroneous idea or individual, as in, "he's all wet."
Applesauce - an explative; same as horsefeathers, As in "Ah applesauce!"
Big Cheese - The most important or influential person; boss. Same as big shot.
Bluenose - An excessively puritanical person, a prude, Creator of "the Blue Nozzle Curse."
Broad- Woman, Dame
Bump Off - To murder, To kill.
Carry a Torch - To have a crush on someone.
Cat's Meow - Something splendid or stylish; The best or greatest, wonderful.
Darb - An excellent person or thing (as in "the Darb" - a person with money who can be relied on to pay the check).
Dame- A Woman
Drugstore Cowboy - a guy that hangs around on a street corner trying to pick up girls.
Dumb Dora - a stupid female.
Fall Guy - Victim of a frame.
Flat Tire - A dull witted, insipid, disappointing date. Same as pill, pickle, drag, rag, oilcan.
Frame - To give false evidence, to set up someone.
Gams - A woman's legs.
Giggle Water - An intoxicating beverage; alcohol.
Gin Mill - An establishment where hard liquor is sold; bar.
Hard Boiled - a tough, strong guy.
Heebie-Jeebies - The jitters.
High-Hat - To snub.
Hooch - Bootleg liquor
Hoofer - Dancer.
Horsefeathers - an explative; same usage as applesauce.
Hotsy-Totsy - Pleasing.
Jalopy - Old car.
Joint - A club, usually selling alcohol.
Keen - Attractive or appealing.
Kisser - Mouth.
Line - Insincere flattery.
Lounge Lizard - a horny dog.
Moll - A gangster's girl.
Ossified - a drunk person.
Pinch - To arrest.
Pushover - A person easily convinced or seduced.
Ritzy - Elegant (from the hotel).
Scram - Ask someone to leave immediately.
Sheba - A woman with sex appeal (from the move Queen of Sheba) or (e.g. Clara Bow).
Sheik - A man with sex appeal (from the Valentino movies)
Soitently- Sure!
Speakeasy - An illicit bar selling bootleg liquor.
Spiffy - An elegant appearance.
Spread Out!- Get out of the way! Give me some room! Stop crowding me!
Stuck On - Having a crush on.
Swanky - Ritzy.
Swell- Wonderful.
Take for a Ride -
Upchuck - To vomit when one has drunk too much.
Wise guy- A Smart Ass
Whoopee - To have a good time.
http://www.angelfire.com/comics/howardfineandhoward/20sTo40sPhrases.html