'grouchy' originates from the word 'grouch', which is believed to have been derived from the Old French word 'grouchier', meaning 'to grumble'.

'grouchier' transformed into the English word 'grouch', and eventually became the modern English word 'grouchy'.

Initially, it meant 'to grumble or complain', but over time it evolved into its current meaning of 'irritable or bad-tempered'.