A more thorough explanation:

Definition: Obsolescent is an adjective used to describe something that is becoming outdated or going out of use.

Example 1: The flip phone is an obsolescent technology, as most people now use smartphones.

Example 2: CDs are becoming obsolescent as more people switch to streaming music online.

These examples illustrate how obsolescent refers to something that is losing popularity or usefulness. The flip phone and CDs were once popular technologies, but as newer and more advanced options become available, they are becoming less common and eventually may become obsolete.