(formal)used especially when politely asking a question or making a suggestion which you hope will not offend anyone (although it may criticize them slightly)（谦辞，表示自己轻率说话）不揣冒昧，恕我无礼；擅自；胆敢
If I may be so bold as to suggest that he made a mistake in his calculations…恕我冒昧说，他的计算有个错误…