Brasil, also known as Hy-Brasil or several other variants, is a phantom island said to lie in the Atlantic Ocean west of Ireland. Irish myths described it as cloaked in mist except for one day every seven years, when it became visible but still could not be reached.
The etymology of the names Brasil and Hy-Brasil is unknown, but in Irish tradition it is thought to come from the Irish Uí Breasail (meaning "descendants (i.e., clan) of Breasal"), one of the ancient clans of northeastern Ireland. cf. Old Irish: Í: island; bres: beauty, worth, great, mighty.
Despite the similarity, the name of the country Brazil has no connection to the mythical islands. The South American country was at first named Ilha de Vera Cruz (Island of the True Cross) and later Terra de Santa Cruz (Land of the Holy Cross) by the Portuguese navigators who discovered the land. After some decades, it started to be called "Brazil" (Brasil, in Portuguese) due to the exploitation of native Brazilwood, at that time the only export of the land. In Portuguese, brazilwood is called pau-brasil, with the word brasil commonly given the etymology "red like an ember", formed from Latin brasa ("ember") and the suffix -il (from -iculum or -ilium).
Nautical charts identified an island called "Bracile" west of Ireland in the Atlantic Ocean as far back as 1325, in a portolan chart by Angelino Dulcert. Later it appeared as Insula de Brasil in the Venetian map of Andrea Bianco (1436), attached to one of the larger islands of a group of islands in the Atlantic. This was identified for a time with the modern island of Terceira in the Azores.