'vasculitis' originates from New Latin, specifically formed from Latin 'vasculum' (a diminutive of 'vas') combined with the Greek suffix '-itis', where 'vasculum' meant 'little vessel' and '-itis' meant 'inflammation'.

'vasculitis' developed as a New Latin medical coinage: Latin 'vas' ('vessel') → diminutive 'vasculum' ('little vessel') plus Greek '-itis' ('inflammation'), and was adopted into English medical terminology as 'vasculitis'.

Initially, the elements referred specifically to inflammation of a small vessel ('little vessel' + 'inflammation'), but over time the term has come to denote inflammation of blood vessels in general and the group of disorders affecting vessel walls.