inbuilt       
adjective mainly UK uk/ˈɪn.bɪlt/ us/ˈɪn.bɪlt/ (US usually built-in)
 内在的,固有的
If something is inbuilt, it is an original part of something or someone and cannot be separated from it, him, or her.
  an inbuilt advantage/problem 内在的优势/固有的问题 
 Synonyms: inherentintegral