Quick answer
Sunniva is a girl name meaning "sun gift".
Meaning and history
Scandinavian form of the Old English name Sunngifu, which meant "sun gift" from the Old English elements sunne "sun" and giefu "gift". This was the name of a legendary saint, an Irish princess who settled on a Norwegian island and was killed by falling rocks after taking refuge from attacking pagans in a cave.
Notes and context
Usage: norwegian