The Spanish word 'puñal' (meaning 'dagger') comes from the Latin word 'pugnale', which meant 'relating to the fist'. This Latin term was derived from 'pugnus', meaning 'fist'. The etymology makes intuitive sense since a dagger is a weapon that is held in and wielded by the fist. The semantic evolution from 'fist-related' to specifically meaning 'dagger' reflects how this hand-held weapon became closely associated with fist-based combat and close-quarters fighting.

Some related Spanish words include 'puño' (fist), 'puñetazo' (punch), and 'empuñar' (to grasp or grip). All these words share the same Latin root 'pugnus' (fist) and maintain meanings related to the hand or fist. While 'puñal' specifically evolved to mean a weapon held in the fist, these related words kept meanings more directly connected to the original concept of a fist or fist-related actions.

English words related to 'puñal' through the Latin root 'pugnus' include 'pugilist' (a boxer or fighter), 'pugnacious' (combative or quarrelsome), and 'impugn' (to attack verbally). These words all derive from the fighting connotations associated with fists. While 'puñal' developed to mean a specific weapon, these English derivatives took on meanings related to fighting or confrontation in both literal and figurative senses.