live off

to use someone or something to provide the money or food that you need to live:
All his life he had lived off his father.
They had learned to live off the land (= grow or find their own food).

Life and living
(Cambridge Advanced Learner's Dictionary & Thesaurus からの live off sb/sth の定義 © Cambridge University Press)

ビジネス英語
to get the money that you need to pay for food, a place in which to stay, clothing, etc. from someone or something:
live off benefits/income/interest
live off earnings/a pension/savings She has been living off her savings since she lost her job in December.
Many young unemployed people are still living off their parents.
(Cambridge ビジネス英語辞典 からの live off sb/sth の定義 © Cambridge University Press)

- Cambridge Dictionary