This is the LMF version of the Apertium English dictionary. Monolingual dictionary for English was generated from the Apertium expanded lexicon of the en-es pair system (English/Spanish). Apertium is a free/open-source machine translation platform, initially aimed at related-language pairs but recently expanded to deal with more divergent language pairs (such as English-Catalan). The platform provides: a language-independent machine translation engine; tools to manage the linguistic data necessary to build a machine translation system for a given language pair and linguistic data for a growing number of language pairs.