1) Degeneration 2) Devolution 1) Desuetude 2) Disuse 
Obsolescence is the state of being which occurs when an object, service, or practice is no longer wanted even though it may still be in good working order. Obsolescence frequently occurs because a replacement has become available that has, in sum, more advantages than the inconvenience related to repurchasing the replacement. Obsolete refers to so...
• (n.) The state of becoming obsolete.
An object's attribute of losing value because the outside world has changed. This is a source of price depreciation.
Falling into disuse; denoting the abolition of a function. ... Origin: L. Obsolesco, to grow out of use ... (05 Mar 2000) ... 
The state of becoming obsolete or out of date. Old-fashioned.
Ob`so·les'cence noun [ See Obsolescent .] The state of becoming obsolete. 
Type: Term Pronunciation: ob′sō-les′ens Definitions: 1. Falling into disuse; denoting abolition of a function.
[n] - the process of becoming obsolete
obsolescence 1. The process of becoming obsolete; falling into disuse or becoming out of date. 2. In biology, gradually disappearing; imperfectly or only slightly developed; a reference to an organ or other part of an animal or plant. 3. A loss in the utility or value of property that results over time from intrinsic limitations (as outmoded faci...
noun the process of becoming obsolete; falling into disuse or becoming out of date; `a policy of planned obsolescence`
Obsolescence refers to an asset?s life or lack there of. When an asset becomes old and outdated, it is considered obsolete and useless. This is a big problem for both manufacturers and retailers.