To be contingent or conditioned; to have something as a necessary condition; to hinge on.
"The success of our new marketing campaign will depend entirely on whether we secure funding from the board before next month."
In plain English: To depend on someone or something means to need them for help, support, or success.
"The project will depend on whether we can secure enough funding."
Usage: Use depend to indicate that an outcome relies on a specific factor, such as saying safety depends on wearing a seatbelt. Ensure the subject of the verb is the thing being influenced, not the person performing the action.
The word "depend" entered English through the Norman conquest via Old French. It originally meant to hang down but replaced the native Germanic word for hanging because it carried a more specific legal connotation of being subject to another's authority.