ait

Etymology 1

From Middle English eyt, eit, from Old English īġeoþ, īgoþ, iggaþ, iggoþ (“ait, eyot, islet, small island”), diminutive of īġ, ēġ, īeġ (“island”). More at eyot.

noun

1. An island in a river, especially the River Thames in England.
   The ait where the osiers grew. 1649, R. Hodges, unknown title
   ‘[H]e the said seigneur, in quality of Lord Paramount, is to all intents and purposes invested with the sole right and property of the river running through his fief, together with […] all the islands and aits within it.’ 1792, Charlotte Smith, Desmond, Broadview, published 2001, page 148
   1833, Johann Wolfgang von Goethe, Autobiography: Truth and Fiction Relating to My Life trans. John Oxenford, book 9, Striking richness of vegetation which follows in the windings of the Rhine, marks its banks, islands, and aits.

Etymology 2

From Scots ait, ate, from Middle English ate, from Old English āte. More at oat.

noun

1. (Scotland) An oat.
   Let husky wheat the haughs adorn, An' aits set up their awnie horn, 1785, Robbie Burns, Scotch Drink