The name Dianne is a girl's name meaning "divine". Dianne and discussed in our forums with posts like "Change two letters (5 names)".
From the experts:
Dianne, one of the many offshoots and variations of the classic Diana, had its moment in the sun in the 1940s--it was a Top 100 name from 1943 to 1952. It now would make a very unlikely choice.
This spelling is currently associated with California Senator Dianne Feinstein.