Dumbfounded
Taken Aback, Astonished
noun
The energy of being shocked fills your body and leaves you dumbfounded. You're so taken aback by this surge of shock that all you can do is stand still and let the energy go through you.
This word uses the kun'yomi reading for one kanji and the on'yomi reading for the other. Just remember that they're the two readings you didn't learn when you learned the kanji and you should be okay.
彼女のおかしな言動に、みんな呆気に取られていました。
Everyone was taken aback by the woman’s odd behavior.