This is the 7007th most frequent German word.
fluss
River.
Here, 'Fluss' denotes the unhindered progress or state of the project, metaphorically implying smooth execution.
Das Projekt befindet sich in einem guten Fluss.
The project is in a good flow.
Here, 'Fluss' refers to a literal river, emphasizing its natural trait and geographical placement.
Der Fluss fließt durch die Stadt.
The river flows through the city.
In this usage, 'Fluss' metaphorically represents the continuity and smooth progression of an abstract concept, like a conversation.