Point-Contact and Crystal Detector
The construction of the point-contact transistor resembles the crystal detector in the crystal radio. You could think of the point-contact transistor as a crystal detector with two whiskers instead of one - the two gold contacts touching the crystal.

The transistor consists of three electrical terminals, one on each gold contact and one on the metal base. The diode, of which the crystal detector was an example, on the other hand has only two terminals. You could therefore refer to the transistor as a triode. As you might already know tri comes from the latin and greek word for three.