deep

1 /di:p/ adjective

1 GOING FAR DOWN going far down from the top or from the surface: a deep hole in the ground | Come on, get in! The water's not very deep here. | 2 metres/6 feet etc deep: At this point the lake is ninety metres deep.

2 knee-deep/ankle-deep etc deep enough to come up to your knees etc: Soon they were in waist-deep mud.

3 GOING FAR IN going far in from the outside or from the front edge of something: He had a deep wound on his forehead. | deep in the forest/mountains etc (=far from the edge of the forest etc): The path led them deep into the forest.

4 FEELING/BELIEF a deep feeling or belief is very strong and sincere: Even Rob's parents regarded him with deep suspicion.

5 run/go deep if a feeling such as hatred or anger runs deep in someone, they feel it very strongly, especially because of things that have happened in the past: Resentment against the police runs deep in the community.

—see also: still waters run deep still 2 (5)

6 SOUND a deep sound is very low: his deep voice | There was a flash and a deep roar.

7 COLOUR a deep colour is dark and strong: the deep blue sky

—compare light 3 (1), pale 1 (2)

8 BREATH ETC a deep sigh 2 gulp 2 etc involves taking a lot of air into your lungs before letting it out again with a loud sound: He took a deep breath and began to sing.

9 SERIOUS

a) someone who is deep or has deep thoughts thinks very hard about things, often in a way that other people find difficult to understand: Hal seems to me to be a very deep, sensitive type of person.

b) a deep book, conversation, thought etc involves serious, complicated, or mysterious subjects that are often difficult to understand: a deep conversation about the meaning of life

10 deep in debt owing a lot of money

11 deep sleep if someone is in a deep sleep it is difficult to wake them

12 be in deep trouble also be in deep shit slang to be in a bad situation because you have done something wrong or stupid: Don't say another word. You're in deep shit already.

13 in deep water in trouble or in a difficult or serious situation: He had an uneasy feeling he was getting into deep water.

14 to be in deep informal to be very involved in a situation, especially one that causes you problems

15 deep in thought/conversation etc thinking so hard, or paying attention to something so much that you do not notice anything else that is happening around you

16 jump/be thrown in at the deep end to choose to do or be made to do a very difficult job without having prepared for it: Our policy is to throw trainee representatives right in at the deep end.

17 go off at the deep end informal to become angry suddenly and violently, usually without good reason

— deepness noun (U) 2 adverb

1 (always + adv/prep) a long way into or below the surface of something; deeply

(+ down/below etc): He pushed his stick deep down into the mud. | Carl was looking deep into her eyes.

2 deep down

a) if you know or feel something deep down, you are sure about it even though you do not admit it: I knew deep down that I would probably never see Marie again.

b) if someone is good, evil etc deep down, that is what they are really like even though they usually hide it: She may seem unfriendly, but deep down she's very nice.

3 deep into the night until very late: They talked deep into the night.

4 two/three etc deep if things or people are two deep, there are two rows or layers of things or people: People were standing three deep at the bar.

3 noun the deep poetical the sea