an ‧ o ‧ rex ‧ i ‧ a /ˌænəˈreksiə/ BrE AmE ( also anorexia ner‧vo‧sa /-nɜːˈvəʊsə $ -nɜːrˈvoʊ-/) noun [uncountable]
[ Date: 1500-1600 ; Language: Modern Latin ; Origin: Greek , from an- 'without' + orexis 'desire to eat' ]
a mental illness that makes someone stop eating