Decisively; bluntly; frankly — used when speaking directly and hitting the core of the matter.
ズバリ言うと、あなたの企画には問題がある。
To be blunt, there are problems with your proposal.
彼女はズバリと本音を言った。
She said her true thoughts bluntly.
面接でズバリ答えることが求められた。
I was expected to answer directly in the interview.
Precisely; exactly — used when something hits the mark or is spot on.
彼の予想はズバリ当たった。
His prediction was exactly right.
質問にズバリ答えられるように準備しておいてください。
Please be prepared to answer the questions precisely.
ズバリ一言で言うと、それは失敗だ。
To put it bluntly in one word: it's a failure.