A primitive root (compare duwach); to be dumb, i.e. (figuratively) dumbfounded -- astonished.
see HEBREW duwach
H1724. daham
[דָּהַם] verb astonish, astound (Arabic , ) —
Niph`al Participle נִדְהָם כְּאִישׁ Jeremiah 14:9 like a man astounded ("" להושׁיע יוכל לֹא כְּגִבּוֺר); ᵐ5 ὑπνῶν נִרְדָּם.