Quote from collector Edward Bunting in the 1800's:

"a peculiar species of chaunt, having a very well-marked time, and a frequently recurring chorus or catch-word. It is sung at the merry-makings and assemblages of young women when they meet at spinning or quiltings, and is accompanied by extraneous verses, of which each singer furnished a line. The intervention of the chorus after each line gives time for the preparation of the succeeding one by the next singer, and thus the Luibin goes round until the chain of song is completed.
"Hence its name, signifying literally 'the link tune' . "

page 98, The Ancient Music of Ireland
Dublin: Hodges and Smith, 1840
re-issued by Dover Publications