Jakob Jakobsen, An Etymological Dictionary of the Norn Language in Shetland…
“ In the last expr., ila is often understood as denoting this kind of fishing. The stone used as an anchor is commonly called ilasten or ilafast. At “ila-fishing” it is, however, not often the custom now to anchor the boat. Edm. gives “eela, iela, a fishing-place or ground for small fish near the shore”; the anchoring of the boat is not mentioned. Here, accordingly, the central point of the original meaning of ila has been lost. — From Du. is reported a pl. form äils [äils] , with anglicised pronunc. ”
