This is the 4342nd most frequent German word.
frühestens
"Frühestens" means "at the earliest."
In this sentence, 'frühestens' is used to indicate the earliest possible time that the action (the meeting's start) can take place.
Das Meeting kann frühestens um 10 Uhr beginnen.
The meeting can start at the earliest at 10 o'clock.
Here, 'frühestens' specifies the earliest possible day when the results will be received.
Wir werden frühestens morgen die Ergebnisse erhalten.
We will receive the results at the earliest tomorrow.
'Frühestens' in this sentence determines the earliest timeframe (next week) when the action (starting the project) is feasible.