noun, masculine/sɛ̃.di.ka.lism/plural: syndicalismes
trade unionism (system or practice of trade unions); syndicalism (movement or doctrine advocating the control of government and industry by trade unions)
“Le syndicalisme est le mouvement qui vise à unifier les travailleurs dans des organisations, les syndicats, pour défendre leurs intérêts communs.” — Trade unionism is the movement which aims to unify workers in organizations, called trade unions, in order to defend their common interests.
From syndical (“pertaining to a trade union”) + -isme.