Foras na Gaeilge was established in 1999 as the cross-border body responsible for the promotion of the Irish language in Ireland. One of the statutory responsibilities of Foras na Gaeilge is the development of terminology and dictionaries. The New English-Irish Dictionary, containing over 48,000 entries and 145,000 senses, is the first major lexicographical project undertaken by the organisation and is available free online at www.foclóir.ie and also as an app. In 2020, Foras na Gaeilge published the Concise English-Irish Dictionary – a print edition of the aforementioned New English-Irish Dictionary. The Concise English-Irish Dictionary contains over 30,000 entries and 85,000 senses.

Foras na Gaeilge have also published the teanglann.ie website; a dictionary website that houses three retro-digitised dictionaries from 1959, 1977 and 1991, along with a comprehensive database of pronunciation and grammar files.

Foras na Gaeilge is also home to An Coiste Téarmaíochta (the National Terminology Committee) who are responsible for the development and maintenance of the National Terminology Database, available at www.tearma.ie.