If you say that someone or something is hideous, you mean that they are very ugly or unattractive.
monstrous , horrible
She saw a hideous face at the window and screamed.
她在窗口看到一张奇丑无比的脸,尖叫了起来。
You can describe an event, experience, or action as hideous when you mean that it is very unpleasant, painful, or difficult to bear.
horrendous
His family was subjected to a hideous attack by the gang.
他一家子遭到了匪帮的可怕袭击。