'hazelnutty' originates from English, specifically the compound of 'hazel' + 'nut' with the adjective-forming suffix '-y', where 'hazel' referred to the hazel tree and 'nut' referred to the edible seed.

'hazel' comes from Old English 'hæsel' (from Proto-Germanic *hasal-), and 'nut' comes from Old English 'hnutu' (from Proto-Germanic *hnutô). The compound 'hazelnut' formed in Middle English, and the adjective 'hazelnutty' was produced later by adding the suffix '-y'.

Initially terms related to 'hazel' and 'nut' designated the tree and its fruit; over time the adjective 'hazelnutty' developed to describe flavors, aromas, or colors reminiscent of hazelnuts and has maintained that specialized descriptive sense.