Which word means to deceive a lover suddenly or callously?

The word that means to deceive a lover suddenly or callously is "jilt." This term specifically refers to the act of ending a romantic relationship abruptly, often in a way that feels harsh or uncaring. It typically implies a sense of betrayal or emotional hurt, reflecting how one partner can unexpectedly drop another, leading to feelings of shock and abandonment.

In this context, "jilt" perfectly encapsulates the idea of a sudden and callous deceit within a romantic relationship, evident in phrases like "jilted lover," which hints at the emotional pain caused by such an action.

The other options, while related to abandonment or leaving, do not carry the same connotation of betrayal in a romantic context. "Forsake" means to renounce or give up something, "surrender" implies giving in or yielding, and "desert" generally means to leave someone without support. None of these communicate the specific nuance of sudden betrayal within a romantic relationship that "jilt" does.