Meaning : Deeply involved.
Example :
Neck-deep in work.
Up to their necks in debt.
Synonyms : neck-deep, up to her neck, up to his neck, up to my neck, up to our necks, up to your neck
Up to their necks ka meaning, vilom shabd, paryayvachi aur samanarthi shabd in Hindi. Up to their necks ka matlab kya hota hai?