obsolesc-, obsolescent-, obsolet- +

1. To become obsolete; to fall into disuse: "This word has not obsolesced, yet, but it is rarely used these days."
2. That which is or is becoming obsolescent.

Having gone through the process of becoming obsolete.

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 The process of becoming obsolete; falling into disuse or becoming out of date.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 facilities) or external circumstances.

Obsolescence is usually distinguished from depreciation and physical deterioration.

4. Economic obsolescence which results from external factors (as location) that render a property obsolete; that is, no longer competitive, unattractive to purchasers or investors, or of decreasing usefulness: "They claimed that the appraisal failed to account for its economic obsolescence because of an adjacent waste facility."
5. Functional obsolescence, deriving from a lack of adequate or appropriate equipment, space, or design.
6. In medicine, the cessation or the beginning of the cessation of any physiologic process.
7. Synonyms of obsolescence: on the way out, passing out of use, disappearing, fading, waning, on the wane, dying.

1. Becoming obsolete; passing out of use, as a word: "He was using an obsolescent term."
2. Becoming outdated or outmoded, as machinery or weapons.
3. In biology, gradually disappearing; imperfectly or only slightly developed. A reference to an organ or other part of an animal or plant.

Describing the process of passing out of use or usefulness; becoming obsolete.

Undergoing the process of becoming obsolete.

1. Old; no longer in use, valid, or fashionable.
2. Superseded by something newer, although possibly still in use.
3. A description of a part or organ of an animal or plant that is undeveloped or no longer functional.
4. A reference to words, equipment, etc., no longer in use; gone into disuse; disused or neglected (often by preference for something newer, which replaces the subject).
5. Synonyms of obsolete: ancient, antiquated, antique, archaic, disused, neglected, old, old-fashioned, out of date, discontinued, defunct, outmoded, and superannuated.
6. Etymology: from Latin obsoletus, "grown old, worn out"; past participle of obsolescere, "to wear out, to grow old, to fall into disuse"; probably from ob-, "away" + solere, "to be used to, to be accustomed".

1. No longer in use or no longer useful; of a kind or style no longer current; old-fashioned.
2. With reference to a plant or animal part, indistinct or imperfect as compared with a corresponding part in related organisms; vestigial (bodily part or organ that is small and degenerate or imperfectly developed in comparison to one more fully developed in an earlier stage of the individual, in a past generation, or in closely related forms).

A condition in which something is out of date and is no longer in current use.

A disused word or phrase; an archaism.

Archaism is a word, expression, practice, or method from an earlier time that is no longer used; or the use of expressions, techniques, and fashions from an earlier period.