In the UK, sure; meaning: grumpy, bad-tempered, in a bad mood - often used when describing older people or teenagers. (But, whatever you do, under no circumstances ask a teenager why they are so grouchy today!😏 - the likely response will go way beyond grouchy...)

Yes, I use it often. Also, "grumpy."

Hello! Yes, I agree, grouchy is definitely good for conventional English. PS I am a teenager :)