As a Noun: 1. The period of time in which you gradually change from being a child into being an adult. English = childhood. 2. Someone who has learned a language as their first language from childhood. English = native, native user, native speaker, native signer. As a Verb or Adjective: 1. To gradually change from being a child into being an adult. English = grow up. 2. To work one's way up in an organisation from a very low position so that you occupy positions of greater power or status. 3. Of a language user, to be have grown up using this language as their first language. English = (be) native.