A guide to 1930s slang for those reading Chasing Eliot Ness:

On the level - honest - telling the truth
Everything's jake - everything will be all right
All right - used instead of "okay" Not alright, but all right
Hooch - booze, illegal liquor
Speak - Short for a speakeasy and a commonly used term. A place where they sold illegal liquor
Dame - a woman
Juice joint - another term for a speakeasy
You follow? - I'm being serious so do what I say
Tommy gun - The Thompson Sub Machine gun - used by gangsters, a holdover from WWI
Snow - Heroin (snorted up the nose back then, not injected)'
Laudanum - An opiate mixture - used to be sold over the counter as a cure all (like heroin) until 1914. Heroin was prescribed as painkiller until 1924 and was commonly used for those who were addicted to morphine (a very common addiction)
Chopper - another term for the tommy gun. Given this nickname because it chopped guys up
Big Bill - The mayor of Chicago during the reign of Al Capone (Big Bill Thompson)
Hop head - a drug addict
Hopped up - on drugs
Swell - great!
Jeepers! - Actually a nicer way of saying Jesus
Insured - Engaged
Insurance - Engagement
Shoddy - a cheap substance made from remnants of clothing that was sprayed on to line coats for those who couldn't afford better
Bread lines - Usually charity kitchens
Get the picture - understand?
Pictures - movies or films
Pony beer - a small beer
Spill it out or spill - tell me! I want to know now!
Skirt chaser - a ladies man
The disease - syphilis (a real epidemic - treated with arsenic - no cure until 1947)
Sheath - a condom
Drive a guy batty - driving someone crazy
Loopy - crazy
Goofy - in love or crazy about someone
Tie bar - used to fasten the tie to the collar so the knot didn't move
Wire or cable - a telegram
Electric light - commonly used because it was still relatively new in some homes
Parlor - front room or living room
On the wire - on the radio
Powder my nose - going to the bathroom
Hock - to send something to a pawn shop. You got a certain amount of time to get this back and then they sold it.
Rock - a ring
In my line - in my type of work
Streetcar - a car that went back and forth on tracks in the city instead of a bus
El - an elevated train (we still have the same lines in Chicago)
Pulling my leg - you're kidding me!
Dough or sugar - money
Being straight - being honest
Machine - often used to describe a car
Sister or sis - men often referred to women they didnt know in this way
First name basis - everyone is Mr. or Miss. or Mrs. unless you gave them your first name and agreed to be on a "first name basis" which was a form of intimacy.
Roadhouse - a speakeasy out in the country
Good girl - a virgin
Sing - to tell the cops what you know
Stool pigeon or snitch - an informant
Wire taps - used to tap through a telephone and any other wire, like a radio
Volstead Act - the act that started prohibition
Repeal - after prohibition ended
Two bit - not worth much
Two bits - 25 cents
Snood - a mesh garment used to tie hair back (late 1930s)
Pipe down - shut up