subsecretary       
noun [ C ] (also sub-secretary) uk/ˌsʌbˈsek.rə.tər.i/ us/ˌsʌbˈsek.rə.ter.i/
 副部长
a person who works for and is slightly lower in rank than the secretary (= the person in charge) of a government department in some countries
  She was a subsecretary in the Ecuadorian Ministry of Energy and Mines. 她曾任厄瓜多尔能源和矿业部副部长。 
 The Mexican sub-secretary of finance explained the government’s policy goal.
 Synonym: undersecretary
 - More examples
 - the Subsecretary of National Defence for the Mexican army
 - He advised various officials in Argentina from the President down to the Sub-secretary of Foreign Affairs.
 - The sub-secretary made all the arrangements for the trip.