expression, godan verb (-u)
speak one's mind; speak frankly; be blunt
Used when someone speaks directly and without hesitation, often about opinions or criticisms. Can imply a lack of tact.
彼は上司にもずばずば言うタイプだ。
He's the type who speaks his mind even to his boss.
ずばずば言うのはいいが
It's fine to be frank, but you should think a bit more about how you say things.