Reference
Definition
What the word means. This is not a work instruction.
A breakaway connection is a listed duct-to-damper connection that can release under fire/thermal movement so the damper stays in the rated wall. It is part of the manufacturer/listed assembly detail, not a normal field choice.
When you see “breakaway connection required,” find the damper submittal/instruction sheet before fastening or sealing.
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.