Longman Dictionary of Contemporary English

Longman Dictionary of Contemporary English (LDOCE) was first published by Longman in 1978. The dictionary is available in various formats: paper only; paper with a bundled premium website; online access only or a gratis online version. LDOCE is an advanced learner's dictionary, providing definitions by using a restricted vocabulary, helping non-native English speakers to understand meanings easily.

The latest version of Longman Dictionary of Contemporary English is the sixth edition. The premium website was revised during 2014 and 2015 and offers over a million corpus examples, exceeding that of the paper version and also supplying sound files for every word and 88,000 example sentences, along with various tools for study, teaching, examinations and grammar. The 9000 most important English words to learn have been highlighted via the Longman Communication 9000.

The gratis LDOCE online was updated to its current layout in 2008 and offers a search (with spelling assistance), definitions; collocations; many examples and pictures.

A key feature of the LDOCE is its utilization of the Longman Defining Vocabulary, a 2000-word controlled defining vocabulary used to write all of the definitions in the dictionary. This defining vocabulary was developed from Michael West's General Service List of high-frequency words and their most common meanings.

The controlled defining vocabulary is not only helpful to second-language learners, but has also facilitated the use of the LDOCE as a machine-readable dictionary in computational linguistics research.

...
Wikipedia