'appendicitis' originates from New Latin, specifically the word 'appendicitis', where 'appendix' (Latin) meant 'that which is appended' and '-itis' (Greek) meant 'inflammation'.

'appendicitis' was formed in the 19th century by combining the Latin word 'appendix' (from Latin 'appendere', meaning 'to hang upon' or 'attach') with the Greek-derived suffix '-itis'; this combination produced the modern English medical term 'appendicitis'.

Initially it referred more generally to 'inflammation of an appendage', but over time it narrowed to the specific meaning 'inflammation of the vermiform appendix'.