1. (言行)未经考虑的，冒失的，没分寸的
    If you describe someone as tactless, you think what they say or do is likely to offend other people.

    e.g. Throughout his school life Darius was tactless and egocentric...
           上学期间，达赖厄斯粗鲁冒失，而且总以自我为中心。
    e.g. He had alienated many people with his tactless remarks.
           他说话没个轻重，得罪了许多人。

1. revealing lack of perceptiveness or judgment or finesse

    e.g. an inept remark
           it was tactless to bring up those disagreeable

    Synonym: inept

2. lacking or showing a lack of what is fitting and considerate in dealing with others

    e.g. in the circumstances it was tactless to ask her age

    Synonym: untactful