Reference
Definition
What the word means. This is not a work instruction.
Fire and smoke dampers are part of a rated life-safety system. Their sleeve, retaining angles, breakaway connection, actuator or fusible link access, wall/floor rating, and manufacturer listing all matter.
If access will be blocked after drywall, hard lid, shaft wall, insulation, or ceiling work, stop and ask early.
This term belongs to rated, life-safety, grease, or structural work. Knowing the word is fine. Doing the work is a red-lane call — get direction before you touch it.