AFAIK the first edition of the Longman Dictionary of Contemporary English (LDOCE), which "uses 2000 common words in the definitions to make understanding easy",

AFAIK the first edition of the Longman Dictionary of Contemporary English (LDOCE), which "uses 2000 common words in the definitions to make understanding easy", was published in 1978. https://www.ldoceonline.com/about.html https://www.ldoceonline.com/about.html