Longman Dictionary of Contemporary English - depth

~ n 1 »DISTANCE« C usually singular, a) the distance down from the top surface to the bottom of something  (What depth is the lake? | to/at a depth of)  (Plant the seeds at a depth of ten centimetres. | a metre/foot etc in depth)  (The pond is no more than a metre in depth.) b) the distance from the front to the back of an object  (The depth of the shelves is about 35cm.) 2 »EMOTION/SITUATION« how strong an emotion is or how serious a situation is  (Lawmakers underestimated the depth of public feeling on this issue.) 3 »KNOWLEDGE« approving the quality of knowing or giving a lot of details about a subject  (I was impressed by the depth and complexity of the book. | The network's news coverage lacks depth. | in depth (=considering all the details))  (We'll need to study the report in some depth.)  (- see also in­depth) 4 be out of your depth a) to be involved in a situation or activity that is too difficult for you to understand  (I felt completely out of my depth when they started discussing philosophy.) b) to be in water that is too deep for you to stand in and be able to breathe 5 be in the depths of despair/depression etc to feel very unhappy 6 the depths of the countryside/forest etc the middle of a place where there are not many people 7 the depths of winter the middle of winter, especially when it is very cold 8 hidden depths a part of someone's character that you do not notice when you first meet them  (I didn't know she wrote poetry - she obviously has hidden depths.) 9 »SEA« the depths literary the deepest parts of the sea