What does the idiom "Vested interest" mean?

• The idiom "vested interest" means - A personal stake in the outcome of a situation.

• vested interest (idiom)
English Meaning: A strong personal interest in the outcome of a situation, often because one stands to gain or lose something as a result.
Bangla Meaning: কোনো পরিস্থিতির ফলাফলে ব্যক্তিগত স্বার্থ বা লাভের সম্ভাবনা।

Example Sentence:
- The politician has a vested interest in the success of the new healthcare bill, as it will benefit his supporters.

Source:
1. Cambridge Dictionary.
2. Accessible Dictionary by Bangla Academy.