assemble
To put parts or people together into one group.
To assemble means to put things together to make something complete, or to gather people in one place.
When you assemble a puzzle, you connect all the pieces until you can see the whole picture. When you assemble a model airplane, you follow instructions to attach wings, wheels, and other parts to create a working replica. Factory workers assemble cars by connecting thousands of parts: engines, doors, seats, and electronics. The word suggests bringing separate pieces together in an organized way to create something functional or complete.
The word also means bringing people together. When a principal assembles students in the gymnasium for an announcement, everyone gathers in one location. A general might assemble troops before a mission. At your school, you probably have assemblies where the whole student body comes together for a special program or presentation.
Assembly is the noun form. An assembly line is where workers put products together step by step as items move past their stations. A school assembly is a gathering of students. And some products come with assembly required, meaning you'll need to put the parts together yourself. The related word disassemble means to take something apart, breaking it back down into its separate pieces.