It is the imperative form of the verb "rechazar", which means "to reject".
Here are some examples of how it can be used:
* No me rechaces, por favor. (Don't reject me, please.)
* Te ruego que no me rechaces. (I beg you not to reject me.)
* Si me rechazas, me romperás el corazón. (If you reject me, you'll break my heart.)
It's important to note that the verb "rechazar" can have different meanings depending on the context. For example, it can also mean "to refuse" or "to decline".