'pastie' originates from Late Latin, specifically the word 'pasticium', where 'pasta' meant 'dough' or 'paste'.

'pasticium' passed into Old French (e.g. 'pastié') and Middle English as 'pasty/pastie', eventually yielding the modern English 'pastie' (with variant spelling 'pasty').

Initially, it referred to a food made from dough (a pastry or pie); over time the word retained that sense and also came to be used metaphorically for a small adhesive cover (the modern burlesque sense).