Na-adjective (keiyodoshi), Noun which may take the genitive case particle 'no', Noun
straight to the point; point-blank; frank; direct
Yojijukugo (four character compound)
もっと単刀直入に言ってくれないかな。隔靴掻痒の感なきにしもあらずだよ。You don't have to leave me hanging like this. Why don't you just come out and tell it to me straight?
Also written 短刀直入【たんとうちょくにゅう】