trade unionist 
(British also trades unionist)
noun
A member of a trade union or an advocate of trade unionism.He had made his name as a militant trade unionist and prominent member of the SPD, which he had joined in 1903 in Hamburg....
- I am a trade unionist in the Natfhe lecturers' union and have been a reader of Socialist Worker for over 30 years.
- Then came the trade unionists, but I was not a trade unionist.
Derivatives
trade unionism
- It is a triumph for militant trade unionism, picketing and solidarity - all the traditions that we are told are outdated.
- I do understand the importance of trade unions and trade unionism.
- It also led in post-war times to a model of trade unionism marked by numerous unions in the same workplace with demarcation disputes and attempts to outmanoeuvre each other for members.