Mainly U.S.: apparently from the name of cities in Georgia and South Carolina. Both are on the Savannah River, ostensibly named with the word for a treeless plain (derived via Spanish from a native South American word). However, the river name may be an adaptation of some other name existing prior to European settlement. The given name may be taken directly from the vocabulary word, more under the influence of its sound than its meaning. In this case, it could be regarded as no more than a fanciful elaboration of Anna or Hannah.