The name Cooper is a girl's name meaning "barrel maker". Cooper and discussed in our forums with posts like "Generation CAF #7".
From the experts:
Cooper is one of the American names used much more often in the US for boys and is also one of the most popular dog names. More than 120 American parents chose it for their baby girls in the most recent year counted....versus nearly 5000 baby boys. For better or worse, it is one of the more masculine-sounding surname-names.