'anorexy' originates from Greek, specifically the word 'anorexia' (Greek 'an- + orexis'), where 'an-' meant 'without' and 'orexis' meant 'appetite/desire'.

'anorexy' changed from the Greek term 'anorexia' and via Medieval/Modern Latin entered English as 'anorexia'; the variant form 'anorexy' developed in English as an alternate noun form, from which the plural 'anorexies' is formed.

Initially, it meant 'lack of appetite' and over time it has kept the same basic meaning of 'loss of appetite' (now often used in medical contexts to refer to anorexia or episodes of appetite loss).