If the question concerns the swords shinigami use in the manga Bleach, then it means "soul cutter".
A Zanpakuto is only a katana with a spirit in it
No, Ichigo's zanpakuto does not change in his hollow form. If you watch the "Zanpakuto Rebellion" arc, you can see this when Ichigo is fighting against the materialised form of Zangetsu, his zanpakuto. Ichigo cannot call on Zangetsu's power, and so he cannot use Bankai. Instead, he releases his hollow form, which is a raw power inside Ichigo. So Ichigo's zanpakuto remains completely unchanged while in hollow form.
I don’t know either but I really wanna know what its called
His zanpakuto is Sōgyo no Kotowari.
No such word in the dictionary, however according to Bleach Wiki, Zanpakutō (with a long O) (斬魄刀) literally means soul-cutter sword.
Makes them see an illusion.
Ichigo's Zanpakuto is called Zangetsu.
Grimmjow's sword name is Pantera!
By cutting them and eliminating with their Zanpakuto
He never has called his Zanpakuto, and I've watched the entire series. It's unlikely to happen, and in his first fight with Ichigo, Kenpachi questioned why Ichigo and Zangetsu fought together, if I remember correctly
Unless he's learnt his Zanpakuto's name, no.
There were a lot of Shakaho's in the Zanpakuto Rebellion Arc.