What term is used for an expression of deep sorrow or regret?

The term "lamentation" specifically refers to the expression of deep sorrow, mourning, or regret, often associated with grief over the loss of a loved one or an unfortunate event. It captures the essence of expressing profound sorrow through vocal or written means, showcasing the emotional weight of such feelings. The root of "lament" indicates an outpouring of grief or regret, making this choice particularly relevant in contexts where sorrow is being articulated.

In contrast, the other terms do not convey the same connotation of sorrow. "Marred" refers to something that has been damaged or spoiled, lacking the emotional depth that "lamentation" embodies. "Innocuous" means something that is harmless or not likely to provoke a strong reaction, which is quite distant from the emotional heaviness of lamentation. Lastly, "miser" refers to a person who hoards wealth and is reluctant to spend it, reflecting a trait related to avarice rather than sorrow or regret. Therefore, "lamentation" is clearly the most suitable term for this particular expression of deep emotional pain.