'ankyl(o)-' originates from Greek, specifically the word 'ankylos', where 'ankylos' meant 'bent, crooked, or stiff'.

'ankylos' passed into Late Latin/Neo-Latin and into modern medical English as the combining form 'ankyl(o)-', used in terms like 'ankylosis' and 'ankylosing'.

Initially, it meant 'bent' or 'crooked' in Greek, but over time in medical usage it evolved to refer specifically to 'stiffness' or 'fusion' of parts (especially joints).