'stencil' originates from Middle English, from Anglo-French 'estencel' (also attested as 'estencile'), ultimately from a Medieval Latin formation similar to 'stencillus', used for a pattern or template.

'stencil' changed from Anglo-French 'estencel' (and Medieval Latin 'stencillus') and eventually became the modern English word 'stencil' through regular sound and spelling changes in Early Modern English.

Initially it referred primarily to the physical template or pattern used for copying designs; over time it came to include the act or result of using that template (the design or marking itself).