A more thorough explanation:

Contra

Contra is a Latin term that means "against" or "contrary to." In writing, it is used as a signal to indicate that the cited source directly contradicts whatever the author just said. It is also known as a negative signal.

Example 1: The author claimed that coffee is bad for your health. Contra, a recent study found that moderate coffee consumption can actually have health benefits.

Example 2: The article argued that climate change is not caused by human activity. Contra, the overwhelming majority of scientific research supports the idea that human activity is a major contributor to climate change.

The examples illustrate how the term "contra" is used to signal a direct contradiction between the author's statement and a cited source. In example 1, the author claims that coffee is bad for your health, but the use of "contra" signals that a recent study found evidence to the contrary. In example 2, the author argues that human activity is not a major contributor to climate change, but the use of "contra" signals that scientific research supports the opposite view.