(idiom) to reach a high level of proficiency or excellence in scholarship or skill; to gradually progress to the highest stage of learning. Literally meaning to 'climb the hall and enter the chamber,' it is also written as [[登堂入室|登堂入室|deng1 tang2 ru4 shi4]].

(idiom) to enter the inner hall to pay respects to a friend's mother; used to describe a very close friendship where two families are treated as one; originally used to describe the friendship between [[周瑜|周瑜|zhou1 yu2]] and [[孙策|孫策|sun1 ce4]] in the [[三国志|三國志|san1 guo2 zhi4]]