In 1643, the Irish Franciscan friar Mícheál Ó Cléirigh published Foclóir nó Sanasán in Louvain (modern-day Belgium), the first dictionary of the Irish language. This monolingual dictionary and language primer was compiled outside of Ireland, reflecting the exile of Irish scholars in continental Europe during the seventeenth century. Ó Cléirigh was a member of the Franciscan order and a key figure in the preservation of Irish language and culture.

Ó Cléirigh's dictionary was a crucial resource for Irish poets, providing them with a standardized reference for their language at a time when Irish was under threat from English colonization. Its publication in Louvain, a center of Irish learning, helped to sustain the Gaelic poetic tradition and enabled Irish poets to continue composing in their native tongue. The dictionary also contributed to the broader effort to preserve Irish literary heritage.