Is a Squib a Muggle?

[harriet_lupin <mlacats@aol.com>]

No: HPFGUIDX 50715

I was having a discussion with a friend about whether Petunia is a 
Squib and she said that a Squib is the same as a Muggle since neither 
one has magical abilities and that's the definition of a Muggle.

I think that squibs are witches and wizards with possibly 'dormant' 
magical abilities.  I guess a muggle can be born from a wizard and a 
witch but I don't really think that that's what a squib is.  I don't 
think Filch is a muggle, for example.

Any thoughts?

Harriet