candid

candid
/ˈkændɪd; `kændɪd/ adj
not hiding one's thoughts; frank and honest 率直的; 坦白而诚实的
    a candid opinion, statement, person 直言、 直说、 直性人
    Let me be quite candid with you
    your work is not good enough. 不瞒你说, 你的工作不怎麽好.

牛津英汉双解词典