Meaning of the word "under ones belt" in English

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

under ones belt

US /ˈʌndər wʌnz bɛlt/
UK /ˈʌndə wʌnz bɛlt/

Idiom

to have achieved or experienced something, especially something that is useful for future work or life

Example:
She already has several successful projects under her belt.
After years of training, he finally had a black belt under his belt.