multi-union       
adjective (also multiunion) uk/ˌmʌl.tiˈjuː.njən/ us/ˌmʌl.tiˈjuː.njən/ /ˌmʌl.taɪˈjuː.njən/
 多个工会的
involving several trade unions (= organizations representing workers)
  the prospect of coordinated multi-union strike action
 Other initiatives included the multi-union campaign against water privatization. 其他倡议包括多工会联合反对水务私有化的运动。 
 - More examples
 - The pattern of multi-union workplaces was changing, with most workplaces either without union representation or represented by a single union .
 - Some unions are combining their efforts in campaigns, such as the multi-union effort at Los Angeles International Airport.
 - Last month there were talks between the National Trade Union Steel Co-ordinating Committee and members of the Teesside multi-union committee.