from Edward Bunting, The Ancient Music of Ireland (Dublin 1840), page 20: The different kinds of Irish harps.
spoken by Gráinne Yeats
Scottish Gaelic lùb spoken by Tony Dilworth
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Lub - A poetical name of the harp.
This is almost certainly for lúb, a perfectly ordinary word for a 'loop, coil, link, twist; craft, deceit'. I have failed to trace the poetic use of it for a harp.
Colm Ó Baoill 2002