Other forms: assembled; assembling; assembles
To assemble means to bring together, as in people or parts. The volunteers assembled to assemble the bikes for the needy kids.
The U.S. Constitution guarantees in something in the Bill of Rights called "the right of assembly." This means that people are allowed to come together for any purpose they chose. In countries without this right, groups who assemble can be disbanded with the idea that they may be assembling a revolution.