Longman Dictionary of Contemporary English

The Longman Dictionary of Contemporary English (LDOCE), first published by Longman in 1978,[1] is an advanced learner's dictionary, providing definitions using a restricted vocabulary, helping non-native English speakers understand meanings easily.

The free online version was updated in 2008 and offers search (with spelling assistance), definitions, collocations, and many examples and illustrations.

[2] This defining vocabulary was developed from Michael West's General Service List of high-frequency words and their most common meanings.

[3] 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.

[4] It is a version of LDOCE specialized for collocations, synonyms, antonyms, designed for intermediate to advanced level learners.