| Name | Kind | Description |
| AbstractMO | class | |
| activity final | activity final | |
| activity final | activity final | |
| AFrame | class | |
| Allocation | class | a directive to place a MObject in a specific way |
| anchor | relation | |
| apply | operation | |
| Architecture | component view | The various Components comprising the Cinelerra3 Video editing Application |
| ARender | class | |
| Assembler | class | |
| AssetManagement | component | |
| AssetManager | package | |
| ATTACH | attribute | attach subject to anchor (e.g. an effect to a clip) |
| Auto | class | |
| Automation Entities | class diagram |