1. It''s disgraceful to say so.
    难于启齿。

2. It was disgraceful to behave like that.
    那种行为很不光彩。

1. 丢脸的：discrepancy犯错误 | disgraceful丢脸的 | disincline厌恶

2. 太丢脸了：- All the need to be loved can't be wrong - Mumble!|- # 需要爱不会错 - 曼波! | Disgraceful!|太丢脸了! | Who do they think they are?|他们算什么东西?

3. 不光彩：lecture sb.说教 | disgraceful 不光彩 | cow's opinion 对牛弹琴

1. （行为、情形等）丢脸的，可耻的，不名誉的
    If you say that something such as behaviour or a situation is disgraceful, you disapprove of it strongly, and feel that the person or people responsible should be ashamed of it.

disgraceful的反义词

    e.g. It''s disgraceful that they have detained him for so long...
           他们把他扣押了这么长时间，真不光彩。
    e.g. I complained about his disgraceful behaviour...
           我抱怨说他的行为丢人现眼。