aitheach Definitions (by source) Show all An introduction to Irish syllabic poetry of the period 1200–1600, with selections, notes and glossary giant; churl. An introduction to Irish syllabic poetry of the period 1200–1600, with selections, notes and glossary. Author: Eleanor Knott. Poems on the O'Reillys a commoner, a boor, a churl; hence ‘a giant,’ ‘a monster’ 109-12 n. Poems on the O'Reillys. Editor: James Carney.