deep ◆◆◇ /diː p/ (deeper , deepest )
1 ADJ If something is deep , it extends a long way down from the ground or from the top surface of something. □ The water is very deep and mysterious-looking. □ Den had dug a deep hole in the centre of the garden. □ Kelly swore quietly, looking at the deep cut on his left hand. □ …a deep ravine. ● ADV [ADV after v] Deep is also an adverb. □ Deep in the earth's crust the rock may be subjected to temperatures high enough to melt it. □ Gingerly, she put her hand in deeper, to the bottom. ● deep|ly ADV [ADV after v, ADV adj/-ed] □ There isn't time to dig deeply and put in manure or compost.
2 ADJ A deep container, such as a cupboard, extends or measures a long distance from front to back. □ The wardrobe was very deep.
3 ADJ [n ADJ ] [as ADJ as ] You use deep to talk or ask about how much something measures from the surface to the bottom, or from front to back. □ I found myself in water only three feet deep. □ The mud is ankle deep around Shush Square. □ How deep did the snow get? ● COMB Deep is also a combining form. □ …an inch-deep stab wound.
4 ADV [ADV after v] Deep in an area means a long way inside it. □ They were now deep inside rebel territory.
5 ADV If you say that things or people are two , three , or four deep , you mean that there are two, three, or four rows or layers of them there. □ A crowd three deep seemed paralysed by the images on these monitors.
6 ADJ [usu ADJ n] You use deep to emphasize the seriousness, strength, importance, or degree of something. [EMPHASIS ] □ I had a deep admiration for Sartre. □ He wants to express his deep sympathy to the family. ● deep|ly ADV □ Our meetings and conversations left me deeply depressed.
7 ADV If you experience or feel something deep inside you or deep down , you feel it very strongly even though you do not necessarily show it. □ Deep down, she supported her husband's involvement in the organization.
8 ADJ [ADJ n] If you are in a deep sleep, you are sleeping peacefully and it is difficult to wake you. □ Una soon fell into a deep sleep. ● deep|ly ADV [ADV after v] □ She slept deeply but woke early.
9 ADJ If you are deep in thought or deep in conversation, you are concentrating very hard on what you are thinking or saying and are not aware of the things that are happening around you. □ [+ in ] Abby was so deep in thought that she had walked past without seeing me.
10 ADJ [ADJ n] A deep breath or sigh uses or fills the whole of your lungs. □ Cal took a long, deep breath, struggling to control his own emotions. ● deep|ly ADV [ADV after v] □ She sighed deeply and covered her face with her hands.
11 ADJ You use deep to describe colours that are strong and fairly dark. □ The sky was deep blue and starry. ● ADJ [usu ADJ n] Deep is also an adjective. □ …deep colours.
12 ADJ A deep sound is low in pitch. □ His voice was deep and mellow. □ They heard a deep, distant roar.
13 ADJ If you describe someone as deep , you mean that they are quiet and reserved in a way that makes you think that they have good qualities such as intelligence or determination. □ James is a very deep individual.
14 ADJ If you describe something such as a problem or a piece of writing as deep , you mean that it is important, serious, or complicated. □ They're written as adventure stories. They're not intended to be deep.
15 ADV If you are deep in debt, you have a lot of debts. □ [+ in/into ] He is so deep in debt and desperate for money that he's apparently willing to say anything. ● deep|ly ADV □ [+ in/into ] Because of her medical and her legal bills, she is now penniless and deeply in debt.
16 PHRASE If you know something deep down or deep down inside , you know that it is true, but you are not always conscious of it or willing to admit it to yourself. □ We knew deep down that we could do it. □ Deep down, we had always detested each other.
17 PHRASE If you say that you took a deep breath before doing something dangerous or frightening, you mean that you tried to make yourself feel strong and confident. □ I took a deep breath and went in.
18 PHRASE If you say that something goes deep or runs deep , you mean that it is very serious or strong and is hard to change. □ His anger and anguish clearly went deep.
19 in at the deep end → see end
20 in deep water → see water
deep|en /diː pən/ (deepens , deepening , deepened )
1 VERB If a situation or emotion deepens or if something deepens it, it becomes stronger and more intense. □ [V ] If this is not stopped, the financial crisis will deepen. □ [V n] Surviving tough times can really deepen your relationship.
2 VERB If you deepen your knowledge or understanding of a subject, you learn more about it and become more interested in it. □ [V n] He did not get a chance to deepen his knowledge of Poland.
3 VERB When a sound deepens or is deepened , it becomes lower in tone. □ [V ] Her voice has deepened and coarsened with the years. □ [V n] The music room had been made to reflect and deepen sounds.