A definite quantity greater than three;cannot be the number two, because you would never use the word "multiple" to define a quantity of 2, although it fits in the definition. You would normally use words such as "pair" or "couple." With the word "Multriple" the listener will automatically know you are speaking of a quantity three or greater.
Yo man, I gave my girl multriple orgasms last night! She was lovin it.