'ataxic' originates from Modern English, ultimately from the medical noun 'ataxia', which comes from New Latin 'ataxia', and originally from Greek 'ataxia' where the prefix 'a-' meant 'without' and 'taxis' meant 'order' or 'arrangement'.

'ataxic' developed from the noun 'ataxia' (recorded in medical Latin/English in the 19th century) and was formed as an adjective meaning 'relating to ataxia'; 'ataxia' itself comes from Greek 'ataxia' (ἀταξία) meaning 'disorder, lack of order'.

Initially the Greek root referred generally to 'lack of order'; over time in medical usage it came to refer specifically to neurological loss of coordinated movement, and 'ataxic' now commonly means 'relating to or affected by ataxia (lack of coordination)'.