閉口頓首 へいこうとんしゅ Meanings Noun, する verb being at a complete loss as to what to do; being at one's wit's end; being at a loss for an answer Kanji 閉 shut. Read as ヘイ. 口 mouth. Read as コウ. 頓 sudden. Read as トン. 首 chief. Read as シュ. Word lists Yojijukugo (四字熟語) Jinuma: Japanese Dictionary · Word lists