呆然
ぼうぜん · bouzen · JLPT N1 · noun
dumbfounded
呆 = dull, stunned; 然 = so, in that state. Sounds like 'bow-zen': bow down in shock, too stunned to speak.
呆 — mouth 口 + tree/wood 木
Originally a variant of 保 (to protect), depicting a person carrying a child. Over time the form simplified to 口 over 木 and the meaning shifted to 'dull, foolish, stunned.' Today 呆 mainly means dumbstruck or slow-witted, as in 发呆 (to space out).