プログレッシブ和英中辞典(第4版)の解説
いき【域】
❷〔水準〕a level;〔段階〕a stage
彼の演奏は素人の域を出ない
His playing is 「no better than that of an amateur [amateurish].
彼の包丁さばきは神技の域に達している
He has attained consummate skill in handling a kitchen knife.
この治療法はまだ実験の域を出ない
This method of treatment is still in the experimental [trial] stage.