After the spending spree of christmas and the holidays, the month of February is used to detox a number of things eg. no alcoholic drinks, dieting, not going out and spending money, generally living like a pleb (a bum).
A: "Come out tonight bro we'll smash some beers and hit the clubs!"
B: "Cant bro, its plebruary.."
A:"Bro wings and nachos at mine for the game!?"
B:"is there salad and water, my life sucks - its plebuary!!"