啃老族

(coll.) adults still living with and depending on their parents

to gnaw / to nibble / to bite

(coll.) to live with and depend on one's parents even upon reaching adulthood

prefix used before the surname of a person or a numeral indicating the order of birth of the children in a family or to indicate affection or familiarity / old (of people) / venerable (person) / experienced / of long standing / always / all the time / of the past / very / outdated / (of meat etc) tough

race / nationality / ethnicity / clan / by extension, social group (e.g. office workers 上班族)