in deep

Idioms  

1. Seriously involved; far advanced. For example, He was in deep with the other merchants and couldn't strike out on his own , or She used her credit cards for everything, and before long she was in deep .

2. in deep water . Also, in over one's head . In trouble, with more difficulties than one can manage, as in The business was in deep water after the president resigned , or I'm afraid Bill got in over his head . These metaphoric expressions transfer the difficulties of being submerged to other problems. The first appears in Miles Coverdale's 1535 translation of the Book of Psalms (68:13): “I am come into deep waters.” The second, which also can signify being involved with more than one can understand, dates from the 1600s. Also see over one's head .

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Example Sentences

Wearing earplugs largely prevented this reduction in deep sleep.

From Science Daily

Dad took the time to shade the feathers in deep black and violet pencil, so that the bird’s wings seem to ripple with motion.

From Literature

There was a crushing in his chest, as if he were being compressed under an opera house—and then suddenly he was in deep rushing water.

From Literature

From its center the palace rose in deep yellow stone, crenellated and ornate, to the sky.

From Literature

Marineland, a once lucrative tourist attraction near Niagara Falls, has said it is in deep financial trouble, cannot afford to care for the whales, and will be forced to euthanize them if it can't find them a new home.

From Barron's