Organizations of workers formed to protect and advance their interests

• Groups negotiating pay, benefits, and conditions through collective bargaining

Acts or states of joining into one; unity or combination

• Conditions of being united for a common purpose

Student organizations at universities for social or political activities

• Campus buildings or bodies providing services and events for students

Joints or fittings that connect parts, especially sections of pipe

• Devices allowing easy assembly or disassembly of connected parts

In set theory, sets formed by combining all elements of given sets

• In computing, data types able to store one of several types