The word 'veteran' originates from the Latin adjective 'veteranus', which itself is derived from 'vetus', meaning 'old'. The core semantic link is between age and experience; something or someone that is old has endured over time, leading to the concept of being seasoned or experienced. In ancient Rome, 'veteranus' specifically referred to old, experienced soldiers, a meaning that was directly adopted into English. Over time, while retaining its primary military association, the term broadened to encompass anyone with long-standing experience in any occupation or skill, thus connecting the ancient notion of age to the modern abstract idea of seasoned expertise.

Structure: veter (old) + an (one belonging to) veter (from Latin 'veteranus', meaning 'old, aged, of long standing'); an (a suffix forming nouns, from Latin '-anus', meaning 'belonging to, pertaining to').