1. Deeply involved
   "up to their necks in debt"
   - neck-deep, up to my neck, up to your neck, up to her neck, up to his neck, up to our necks

See also: involved

• two-time
• two-timer
• two-timing
• two-toe
• two-toed
• two-toed anteater
• two-toed sloth
• two-tone
• two-up
• two-way
• two-way street
• two-wheel
• two-wheeled
• two-wing flying fish
• two-winged insects
• two-year
• two-year-old
• two-year-old horse
• twofer
• twofold
• twonk
• twopence
• twopenny
• twopenny-halfpenny
• twoscore