a)UNDERSTAND#to be involved in a situation or activity that is too difficult for you to understand or deal with 不能理解,超出本身的能力
I felt completely out of my depth at the meeting.
我在会上感到自己一点都听不懂。
b)WATERBritish EnglishBrE to be in water that is too deep for you to stand in 【英】在水深没顶的地方
Examples from the Corpus
be out of your depth• All went through him, and the hapless McCann, theoretically marking him, was out of his depth.• But he is out of his depth.• I tried to read the report, but I was way out of my depth.• I was hopelessly out of my depth in collegechemistry classes.• While the old hands somehow muddle through, novicesare out of their depth within minutes.• She was out of her depth in the advancedclass, so they moved her to the intermediate class.