Have You Seen A Diac Before?
Above are the sample of Diac photos and you have to take note that certain Diac may come in the form like a normal signal diode. If you could see a center line across the component then you can be certain that it is a Diac. Otherwise you need to refer the part number with the help of semiconductor databook to confirm the component. Set your meter to X10 K ohm using analog meter and it should have no reading either way. It can be found in blender and in light dimming circuit.