Meaning of “inasmuch as” - Learner’s Dictionary

inasmuch as

conjunction us uk /ɪnəzˈmʌtʃˌəz/ formal

used to introduce a phrase that explains the degree to which something you have just said is true:

They were strict about our appearance inasmuch as we weren't allowed to wear jewellery or make-up.

(Definition of “inasmuch as” from the Cambridge Learner’s Dictionary © Cambridge University Press)