'arrowy' originates from English, specifically the word 'arrow' plus the adjectival suffix '-y', which forms adjectives meaning 'having the quality of' or 'like'.

'arrow' changed from Old English 'earh' (or variants such as 'earh-') and derives from Proto-Germanic roots (reconstructed as *arhwiz or similar); over time it became the Modern English 'arrow', and the modern adjective 'arrowy' is formed by adding '-y' to that noun.

Initially, 'arrow' referred to the projectile used with a bow. Over time, derivative adjective forms like 'arrowy' came to mean 'arrow-shaped' or 'having the qualities of an arrow' (including figurative senses such as 'sharp' or 'piercing').