"Elf" etymology and Albus Dumbledore

[potioncat]

No: HPFGUIDX 160629

Carol wrote:
(snipping, because I'm supposed to)
Did JKR know? Did she name Dumbledore
> Albus for this reason? Might the Dumbledore brothers have a distant
> house-elf ancestor, which might account for Albus Dumbledore's ability
> to do wandless magic? 

Potioncat:
Once upon a time, folks around here thought DD wanted socks because 
they would set him free. Now you've found another connection to house-
elfdom. And I've heard, for the second time, Dobby say how proud he was 
to keep Professor Dumbledore's secrets. (GoF)

As for wandless magic. Haven't we also seen Snape and possibly Lupin 
perform wandless magic?