No no no, it is neither a Gunblade nor a Bladegun, it is both a gun and a blade. Got it memorized?
To clarify: Gunblade = Blade which resembles a gun, thus the gun- prefix.
Bladegun = Gun which resembles a blade, similar to the "Velvet Nightmares" used by those three guys in Advent Children.
So Lightning's weapon is really a sort of gunblade/bladegun combo.
