Clarence Barnhart

Clarence Lewis Barnhart (1900–1993) was an American lexicographer best known for editing the ''Thorndike-Barnhart'' series of graded dictionaries, published by Scott Foresman & Co. which were based on word lists and concepts of definition developed by psychological theorist Edward Thorndike. Barnhart subsequently revised and expanded the series and with the assistance of his sons, maintaining them through the 1980s. Provided by Wikipedia