'emphasize' originates from Modern English, ultimately from Greek, specifically the Greek word 'emphasis' (ἐμφάσις), where 'em-' meant 'in' and the root related to 'phainein' meant 'to show'.

'emphasize' entered English in the late 16th to early 17th century via Middle English and Modern French formations from Greek 'emphasis' and Late Latin/French verbal formations (for example influences like French 'emphaser'), and eventually became the modern English verb 'emphasize'.

Initially, related words meant 'a showing, an appearance' or 'making something prominent'; over time the verb developed the current meaning of 'to give special importance to' or 'to stress'.