Complex sentence: The island's name is an anglicisation of the Gaelic "Innis Mearnaig" meaning' Island of Saint Marnock', a holyman who lived on the island for a time in the 7th Century and established a chapel here.
Split into simpler sentences: The island's name is an anglicisation of the Gaelic "Innis Mearnaig" meaning "Island of Saint Marnock". Marnock was a holyman who lived on the island for a time in the 7th Century and established a chapel here.