in deep

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 .

Example Sentences

"If this potassium signature is preserved, we would want to look for it in deep time and deep Earth," Nie says.

Read more on Science Daily

Pliley said she reached out to the Texas State professor who taught the LGBTQ+ communications course Harrison posted about and described her to be in “deep deep distress.”

Read more on Salon

Trent Alexander-Arnold's World Cup hopes were already in deep trouble even before he sustained the hamstring injury that has interrupted the start to his Real Madrid career.

Read more on BBC

Their results revealed that older adults exhibit stronger microvascular pulsations in deep white matter compared to younger individuals, and that hypertension further intensifies these effects.

Read more on Science Daily

A year or so ago, the Scottish National Party looked to be in deep trouble.

Read more on BBC