It's new to me as a name, but obviously as a word it's an adjective meaning With a structure like coral.
As a French name, I'm familiar with Coralie - also means, basically, coral - and I like it very much. Not so sure about Coralline, though - seems a bit overelaborate for my simple tastes. Interesting how names develop, isn't it? I knew a woman whose granddaughter should have been Carol for dynastic reasons, but they sensibly named her Coral instead giving her individuality along with the family links.