プログレッシブ和英中辞典(第4版)の解説
ぼうげん【妄言】
〔うそ〕a lie, a falsehood ⇒うそ（嘘）；〔いいかげんな言葉〕a remark made off the top of one's head
妄言多謝
〔手紙で〕I hope you will forgive my brashness (in making the above suggestions).（▼出過ぎた言葉を詫びる）／Please excuse me for expressing myself candidly.（▼率直に言ったことを詫びる）
もうげん【妄言】
a rash, thoughtless remark
妄言多謝
Many apologies for my imprudent [indiscreet] remark.