'arr' originates from English, specifically the imitative exclamation 'ar' (also attested as 'argh'), where the sound was used to express anger, pain, or exertion.

'arr' changed from earlier English exclamations such as Middle English 'ar'/'ah' used to express sorrow or anger and was later reinforced in popular culture (notably 19th–20th century literary and theatrical portrayals of pirates) to the stereotypical pirate utterance 'arr'.

Initially it meant 'an expression of grief, anger, or pain', but over time it evolved into its current meaning of 'a general exclamation of frustration and a stereotypical pirate vocalization.'