infant [LME] This is from Latin in- ‘not’ and fari ‘to speak’ via French enfant. According to law, an infant is a person who has not reached the age of legal majority, so is unable to speak for themselves in law. The Italian equivalent infante meant ‘youth’ and also ‘foot soldier’, from which arose infanteria, a body of foot soldiers. English adopted this as infantry in the late 16th century.