The name Lenny is a boy's name meaning "brave lion". Lenny and is often added to user-created lists like Boy's names McCharlie and discussed in our forums with posts like "Quick Question Thread?!".
From the experts:
Nickname of yesteryear now saddled with all manner of unattractive associations. Any Leonard of today would be called Leo, or maybe Leon or Leonard (or much more fashionably, Leonardo).