custam Definitions (by source) Show all Aibidil Gaoidheilge & Caiticiosma: Seaán Ó Cearnaigh's Irish primer of religion, published in 1571 “vectigal”, ‘tax’; cusdum 54.17, 54.18 Aibidil Gaoidheilge & Caiticiosma: Seaán Ó Cearnaigh's Irish primer of religion, published in 1571. Editor: Brian Ó Cuív.