1. A passionate or emotional expression of sorrow or grief: Jim requested the pastor to have a special song to be sung by the church choir that expressed his laments during his mother's funeral.
2. A presentation of regret or disappointment; a complaint: Dorothy let the store know with her laments about the poor quality of the food mixer that she had purchased a week ago.

To mourn or to express regret about a loss or death of someone: Henry and Sally were lamenting with great sorrow and tears about the death of their little son who was run over by a car while he was crossing a street.