scand from Severin ’serious’ or from Sigrid 'victory+beauty'
(as a greek name, from the sirens, mermaids): The sirens was deadly-dangerous bird-women, seductresses, who lived on an island. Seamen who sailed near were decoyed with the Sirens' enchanting music to shipwreck on the rocky coast.
+ book "Sirens of Titan", Kurt Vonnegut