Which term implies a strong feeling of regret?

The term "lament" specifically refers to expressing sorrow or regret, particularly in a vocal or demonstrative manner. When someone laments, they are often mourning a loss or reflecting deeply on something they wish had happened differently. This term embodies a strong feeling of regret, making it the best choice in this context.

In contrast, "impetuous" describes someone acting quickly and without thought, usually in a rash manner, which does not convey regret. "Idolatrous" pertains to excessive admiration or devotion to something, often in a religious or metaphorical sense, and does not relate to feelings of remorse. "Latent" refers to something present but not visible or active, and does not convey any emotional connotation related to regret. Thus, "lament" stands out as the most accurate term to describe a strong feeling of regret.