1. Accounting: (1) Fixed assets (excluding real estate) that has limited (though not necessarily predetermined) useful life and is, therefore, subject to depreciation. (2) Natural resource such as coal, gas, oil, ores, timber, that diminishes in value due to depletion, extraction, or removal and is, therefore, subject to amortization.
2. Securities industry: put option or call option whose value expires on a fixed date.