See also: Modify
A tweak is a minor progress modification. It could be a slight change in design or the steps taken to make something stable.
A tweak would include fine-tuning controls and any small alteration to a configuration, setting, preferences, etc.
To tweak something is to make such a change. Tweaking is used for troubleshooting or simply for just hacking around.
TakeDown.NET -> “Tweak”