IPA: /səˈpɜrflʊəsli/
KK: /sʊˈpɜrflʊəsli/
In a way that is unnecessary or excessive, going beyond what is needed.
He explained the project superfluously, adding details that were not required.
Superfluously → It is formed from "super-" (meaning above or over) and "fluere" (meaning to flow). The word describes something that flows over or beyond what is necessary, hence excessive or unnecessary.
Think of something that flows 'above' ('super-') what is needed ('fluere') — that's why superfluously means excessively.