Cleo

Cleo, one of the few girls' names to boast the cool-yet-lively o ending, is of course short for Cleopatra, the name of one of the most powerful women in history.

Cleo was most popular in the early decades of the twentieth century--when it was also used for boys. A distinguished bearer is the British jazz singer Cleo Laine, and there have been Cleos on two TV dramas: ER and Law & Order: Special Victims Unit.

Maybe the fact that Cleo was recently chosen by Friends' David Schwimmer will ignite a welcome revival.