'argyraspides' originates from Ancient Greek, specifically the word 'ἀργυράσπιδες (argyraspides)', where 'argyros' meant 'silver' and 'aspis' meant 'shield'.

'argyraspides' was borrowed from Ancient Greek (via Latinized forms used by classical writers) into modern historical usage in English to name that particular corps; the form has been preserved more or less unchanged as a borrowed proper/historical name.

Initially it literally meant 'silver shields' (soldiers bearing silver-decorated or silver-backed shields); over time it became a fixed name referring to that elite unit and is used in historical writing rather than as a descriptive phrase.