'frosty' originates from Old English, specifically the word 'frostig,' where 'frost' meant 'frost' and '-ig' was a suffix meaning 'having the quality of.'

'frostig' changed from Old English to Middle English as 'frosti' and eventually became the modern English word 'frosty'.

Initially, it meant 'covered with frost,' but over time it evolved to also mean 'unfriendly or cold in manner.'