What is Total Loss?

Legal Definition
In insurance, a total loss or write-off is a judgment, by the insurer, that the lost value or repair cost of a damaged property exceeds the value of its policy, resulting in what it concludes is a "total loss" or "constructive total loss" A constructive total loss factors other incidental expenses beyond repair, such as salvage. Policies covering homes, vehicles and other non-investment assets subject to depreciation typically pay the insured only a fraction of the cost of replacing the property, meaning they could become "total losses" even though some value remains. About one in seven car accident claims results in a "total". Totaled properties are usually demolished or torn down, scrapped, or recycled for parts after their policies are settled.
-- Wikipedia
Legal Definition
A technical expression, importing an utter loss of the property for the voyage, and no more. 1 T. R. 187. Vide Loss, and 2 Phil. Ev. 54, n.; 16 East, R. 214 Park's Ins. Index, h. t.; Marsh. Ins. 486.
-- Bouviers Law Dictionary
Legal Definition
In marine insurance, a total loss is the entire destruction or loss, to the insured, of the subject-matter of the policy, by the risks insured against As to the distinction betwcen "actual" and "constructive" total loss, see infra. In fire insurance, a total loss is the complete destruction of the insured property by fire, so that nothing of value remains from it; as distinguished from a partial loss, where the property is damaged, but not entirely destroyed.
See also
-- Black's Law Dictionary
Legal Definition
Such damage to a building that it no longer exists as a building. See 66 Tex. 103, 59 Am. Rep. 613, 18 S. W. 337. A vessel so damaged that a prudent uninsured owner would not undertake to rebuild her. See 90 Tex. 170, 59 Am. St. Rep. 797, 35 L. R. A. 672, 37 S. W. 1068.
-- Ballentine's Law Dictionary