n.1. The act or an instance of losing: nine losses during the football season.
2. a. One that is lost: wrote their flooded house off as a loss.
b. The condition of being deprived or bereaved of something or someone: Her loss was made easier by the support of her friends.
c. The amount of something lost: selling at a 50 percent loss.
3. The harm or suffering caused by losing or being lost: The doctor's retirement is a great loss to the community.
4. losses People lost in wartime; casualties.
5. Destruction: The war caused incalculable loss.
6. Electricity The power decrease caused by resistance in a circuit, circuit element, or device.
7. The amount of a claim on an insurer by an insured.
at a loss1. Below cost: sold the merchandise at a loss.
2. Perplexed; puzzled: I am at a loss to understand those remarks.