The prefix contra- and its variant counter- mean “opposite” or “against.” For instance, the prefix contra- gave rise to the words contradict and contrast, whereas the variant spelling counter- gave rise to counteract and counterfeit. To contradict someone is to speak “against” what she is saying, whereas a counterclockwise direction is “opposite” of the normal way a clock’s hands usually run.
Like this? Build a competent vocabulary with Membean.