The name Catriona is a girl's name of Gaelic origin meaning "pure". Catriona and is often added to lists like British Girl Names and discussed in our forums with posts like "Girls Makeover - Two Middles".
From the experts:
This Katherine variation, used through Ireland and Scotland, is pronounced as Katrina -- kat-tree-na. The name became popular after the Crusaders brought home stories about the colorful fourth century martyr, Catherine of Alexandria. Its later popularity increased following the success of Robert Louis Stevenson's 1893 Catriona, the sequel to Kidnapped. Pronunciation is like Katrina.