What is a spade lug?

Answer 1

It is a type of electrical connectors that is meant to be joined with its mating half. The spade terminal is retangular and flat appearing similar to a spade digging tool. It relies on tension not mechanical tightening. The "spade" part is the "male" and the "female" half slides over the spade. Some people refer to it as "push-on" These are only meant for small size wires usually no more than size#10. They are common in vehicle, appliance and machinery applications.