Meaning of the word "once a thief always a thief" in English

What does "once a thief always a thief" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

once a thief always a thief

US /wʌns ə θiːf ˈɔːlweɪz ə θiːf/
UK /wʌns ə θiːf ˈɔːlweɪz ə θiːf/

Idiom

a proverb meaning that a person's character, especially a bad one, is unlikely to change

Example:
Even though he served his time, some people still believe that once a thief, always a thief.
She tried to trust him again, but his past actions made her think, 'Once a thief, always a thief.'