'annulate' originates from Latin, specifically the word 'annulatus', where 'annulus' meant 'ring'.

'annulate' changed from Medieval/Neo-Latin 'annulatus' and entered scientific English (from Latin) as 'annulate' in modern usage.

Initially it meant 'provided with rings' (related to 'ring'), and over time it has retained that core idea, coming to mean 'having rings or being marked with rings' or 'to mark with rings'.