It means... -he is like my best mate.

意思是…-他是我最好的小伙伴。

youdao

Food is the best mate in the lovelorn time.

失恋的时候，食物就是最好的伴侣。

youdao

Nice knowing you big guy, all the best mate.

认识你真棒，大个头，来自最好的蓝军球迷。

youdao

Best mate Gary Neville broke his shortly afterwards and missed the whole World Cup.

BBC: WHEN THE INJURIES HAPPENED

Throughout the series he and his best mate Andrew Flintoff led the way with raw hostility and aggression.

BBC: Justin Langer column

Just weeks earlier, the amiable Culloty won the Gold Cup aboard Best Mate.

BBC: Jim Culloty