'drafty' originates from English, specifically the word 'draft' + the adjectival suffix '-y', where 'draft' meant 'a current of air' (from the noun sense of 'draft').

'drafty' changed from Middle English forms such as 'draughty' (from 'draught', Old English 'dræft') and eventually became the modern English adjective 'drafty' (with alternate spelling 'draughty' persisting in some dialects).

Initially, it meant 'characterized by a draught (a current of air)', and this meaning has remained essentially the same in modern usage.