also: めんもくまるつぶれ
expression
complete loss of face; total humiliation
Describes a situation where one's honor or reputation is utterly destroyed, often in public. Stronger than 面目を失う.
彼は会議で大失敗して、面目丸つぶれだった。
He made a huge blunder at the meeting and suffered a complete loss of face.
あんなミスをしたら、面目丸つぶれだよ。
If you make a mistake like that, it's a total humiliation.
Compound of 面目 (めんぼく, 'face, honor') + 丸つぶれ (まるつぶれ, 'completely crushed'). The 丸 intensifies the destruction, giving the sense of total loss.