What is the Japanese term for hands in a form of martial arts?

Karate

Kara is a character that can be translated as China or Empty.

Te translates as Hand.

Karate evolved as a combination of the local Okinawa art of Te, a form of combat combined with Chinese White Crane Kung Fu.

In the early part of the century, the lead martial artists on Okinawa got together and agreed that they should use the term Empty, one reason be to avoid issues with the Japanese that were taking control of the area.
Karate, also know as the way of the empty hand.