'valgus' originates from Latin, specifically the word 'valgus', where it meant 'bent outward' or 'knock‑kneed'.

'valgus' was used in Latin with the meaning 'bent outward' and was adopted into New Latin/medical Latin; from there it entered English medical terminology as 'valgus'.

Initially, it meant 'bent outward' in Latin, and over time it has retained that core sense in modern medical usage to describe outward angulation of bones or joints.