The Spanish word 'capitán' (meaning 'captain') traces back to the Latin word 'caput' meaning 'head'. From 'caput', the Latin adjective 'capitalis' was formed, meaning 'principal' or 'chief'. This evolved into the Late Latin term 'capitanus', meaning 'chief' or 'captain', which finally developed into the Spanish 'capitán'. This etymology reflects how the concept of a 'captain' is connected to being the 'head' or leader of a group.

Several common Spanish words share this same Latin root 'caput' (head). For example, 'cabeza' (head), 'capital' (capital city), and 'cabo' (corporal, or literally 'head of a small unit') are all related words that Spanish learners might recognize. Each of these words maintains a connection to the concept of being at the 'head' of something, whether literally or figuratively.

Many English words are related to 'capitán' through the same Latin root 'caput'. The most obvious is 'captain' itself, but others include 'capital' (both the city and the financial term), 'cap' (something that goes on your head), 'chief' (the head of a group), and 'chapter' (originally meaning the head or top of a page). The concept of 'head' or 'leading' is preserved in all these related terms.