undersecretary
 oxford
 views  updated May 11 2018un·der·sec·re·tar·y  / ˌəndərˈsekriˌterē/ • n. (pl.  -tar·ies) a subordinate official, in particular (in the U.S.) the principal assistant to a member of the cabinet, or (in the UK) a junior minister or senior civil servant.
 The Oxford Pocket Dictionary of Current English