noun
rival labor union; second union
Refers to a union formed in competition with an existing union, often within the same company or industry. Common in labor relations contexts.
会社には第一組合と第二組合が存在する。
There are a first union and a rival union at the company.
第一組合 is the original or primary union, while 第二組合 is a rival or breakaway union.
Compound of 第二 (second) and 組合 (union). The term is transparently derived from its components.