Elver means in slang: – Baby eels

It is often called an urban elf by some.
(in Slang Dictionary, added by Mitchell Briggs)

What else does Elver mean?

You can read Memoirs of the Geisha to see how the Petite Cock interacted with the Geisha. It is similar to an eel moving through a cave to find the perfect spot, and then spitting in the area it finds most appealing. COCK:EEL::BABY COCK:ELVER.
(in Slang Dictionary, added by Reed Figueroa)

Elver is a great friend, lover and confidant. Elver will be there for you. He is kind, and if he needs to, he will. But, I don’t think he can be faulted for being kind. Overall, elver makes a wonderful friend.
(in Slang Dictionary, added by Kristopher Rubio)

Young eel in fresh and brackish water.
(in Merlin Dictionary)