Used in blues, classic, country, disco, grunge, hip-hop, jazz, latin, rap, rock, swing, techno and rap.
The Locrian has a lot to offer; it is only a half tone either away above and below the Tonic key; i.e. the Relative Minor is a half tone below and the Tonic Minor is a half tone above. Sweet!
But I have absolutely no idea where the word comes from. But if your intention is to learn all there is about the Locrian, this book will show you how to use the information when using it to create the improvised line.
It lists the alterations ending with the 7th (Locrian) note of a scale; creating Locrian Cadences.