The Spanish word 'hermana' (meaning 'sister') traces back to the Latin word 'germanus', meaning 'genuine' or 'natural'. This Latin term itself derives from 'germen', meaning 'sprout' or 'bud'. The word evolved through Old Spanish 'ermana' before taking its modern Spanish form 'hermana'. The semantic evolution from 'genuine/natural' to 'sister' likely stems from the concept of siblings being naturally related by blood.

A closely related Spanish word is 'hermano' (brother), which shares the same Latin root 'germanus'. Together, 'hermano' and 'hermana' form a natural pair referring to siblings, maintaining the original sense of 'genuine' or 'natural' relation.

While English 'sister' is not related to 'hermana', we can find the Latin root 'germen' in English words like 'germ' (originally meaning a seed or sprout before taking on its modern meaning of a microorganism), 'germinate' (to sprout or begin to grow), and 'germane' (meaning relevant or appropriate, from the same Latin 'germanus' that gave us 'hermana', preserving the sense of something being naturally connected or related).