'armigerous' originates from Latin, specifically the Late Latin word 'armiger', where 'arma' meant 'arms' and 'gerere' meant 'to bear'.

'armiger' passed into Medieval/Old French and Middle English usage as a term for an 'armor-bearer' or one entitled to bear arms; English formed the adjective 'armigerous' by adding the suffix '-ous' to this stem.

Initially it referred to someone who bore or carried arms (an armor-bearer); over time it evolved to mean 'having or entitled to bear heraldic arms' (i.e., possessing a coat of arms).