Triangle man — A YMCA worker. One of the kinder euphemisms the doughboys had for the YMCA, an organization that the doughboy did not hold in high regards.
He’s Jake with me — A right guy, or someone you can depend on. “That Travis Haymaker, he’s Jake -with me. ”
To the mustard — Also someone you can depend on or something that is acceptable. “Tim Carr is to the mustard. ”
On the square — Someone you can depend on, or honest “Mickey is a squad leader who is on the square!” “Sure we had some bad numbers — you always do — but by and large we were on the square. ”
Sam Browne — Enlisted slang for officers for the Sam Browne belts they wore.
Raising the old Harry — Causing trouble or raising a ruckus. “That Poncho Villa was raising the ol’ Harry down on the border. “
But it was no soap — An event or a plan that didn’t happen or take shape. “Some of the boys wanted to get over to Paris, but it was no soap. ”
In the soup — To be in trouble. “It’s a good thing the Germans didn’t ‘t hit us or we ‘d be in the soup. ”
Joe Latrinsky — “Captain of the latrine” it means a rumor. “According to Joe Latrinsky we are going over the top.”
These slang terms were gleaned from the book “Make the Kaiser Dance; The American Experience in World War I ” By Henry Berry. Berry’s book is a collection of interviews made with AEF veterans in the mid-1970’s.