knee-deep

adjective3

1. •
   Reaching up to the knees.

   • High above stood the ash-tree, its boughs covered with the toy-like bunches called "locks and keys;" and beyond spread the meadows, knee-deep with the verdant grass. — 1831
2. •
   Submerged to the knees.

   • This gave me a hint, and I went knee-deep, and sometimes neck-deep, in the Red Weed. The density of the weed gave me a reassuring sense of hiding. — 1898
3. •
   (figurative) Deeply involved (in something) or preoccupied (with something).

   • By the time Tracey arrived, Kayla was working on her second cup of café mocha and knee-deep in paperwork. — 2007