unionize
verb [ I or T ]
HR, WORKPLACE (UK also unionise) /ˈjuːniənaɪz/ ukusto form a trade union, or to organize workers into a trade union:
Nurses at the hospital have been trying to unionize since 2009.
Attempts to unionize the car plant have failed so far.
The local economy in LA is becoming more fragmented, with smaller companies whose workers are harder to unionize.