If any cost have both fixed cost and variable cost features, then it will be semi variable cost. We can give the example of electricity cost. Up to some limit, we have to pay the bill whether we consume electricity or not after some limit, cost will be on the basis of unit consumed. We can also give the example of salesman's earning. Salesman gets a fixed salary. He also gets commission on sales.
You can also read the following types of Cost :
4. Fixed Cost