Meaning of the word "self described" in English

What does "self described" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

self described

US /ˌself dɪˈskraɪbd/
UK /ˌself dɪˈskraɪbd/

Adjective

described by oneself in a particular way, often without external validation

Example:
He is a self-described expert in ancient history.
The company is a self-described leader in sustainable technology.