I don't think a monolith is defined by coupling. I think it's defined by being a single deployment of custom code covering many domains/including many kinds of

I don't think a monolith is defined by coupling. I think it's defined by being a single deployment of custom code covering many domains/including many kinds of functionalities, rather than many deployments. Your definition of uncoupled makes some sense. It's a good starting place at the very least.