From grouch + -y. Originally US college student slang.
Grouchy Sentence Examples
I'm just in a grouchy mood this morning.
He found that Grouchy had made little progress beyond the town.
Sleep late and wake up grouchy.
You won't have many chances in life to get a free pass for being grouchy, so enjoy it while you can.
Meanwhile two long hours had been wasted on the right whilst Grouchy and Vandamme deliberated over their plan of action in front of the Prussian brigade at Gilly; and it was not until the emperor himself again reached the front, about 5.30 P.M., that vigour replaced indecision.