buddy
n. countable C1 Advanced Oxford US //ˈbədi// UK //bˈʌdi// bud·dy
n. a friend. You use this word for someone you know well and like, especially a male friend.
n. a close friend or companion. Informal in register; frequently used as a term of address between males.
He is going to the cinema with his old school buddy.
We have been hiking buddies for years and try to explore a new trail every weekend.
The program pairs each new employee with a workplace buddy to help them navigate the company culture during their first month on the job.
Usage
Often used as a vocative ('Hey, buddy') or in compound nouns like 'study buddy' or 'gym buddy'.