'armet' originates from Italian, specifically the word 'elmetto,' where 'elmo' meant 'helmet' and the diminutive suffix '-etto' meant 'small'.

'armet' changed from Italian 'elmetto' (a diminutive of 'elmo') through Late Medieval/Old French usage into Middle English as 'armet' and eventually became the modern English word 'armet'.

Initially, it meant 'a small helmet,' but over time it came to refer more specifically to the 15th-century close-fitting helmet with hinged cheek pieces now described as an 'armet'.