Upstream Merge
Noun · Open Source
Definitions
The act of merging changes from an upstream project into a downstream fork, branch, or maintained copy. In long-lived forks, upstream merges are where divergence costs become painfully visible.
In plain English: Merging changes from the upstream project into a local fork or copy.
Example: "The quarterly upstream merge took longer than expected because years of local patches had drifted away from the assumptions in the main project."