{adv. phr.} Overwhelmed with; submerged in. * /"During the summer season in our cottage by the lake," the Allens complained, "we are usually up to our necks in uninvited guests."/ Compare: UP TO ONE'S EARS.
UP TO ONE'S NECK
Meaning of UP TO ONE'S NECK in English
Slang English vocab. Английский сленговый словарь. 2012