This is the 1090th most frequent Polish word.
mocy
"Mocy" is the genitive or dative case of "moc," meaning "power" or "strength."
Here, 'mocy' refers to 'power', denoting its presence and effect.
Siła mocy była odczuwalna w całym pomieszczeniu.
The power's strength was felt throughout the entire room.
In this case, 'mocy' means 'force', specifically referring to legal effectiveness.
Decyzja jest już w pełni mocy prawnej.
The decision is already in full legal force.
Here, 'mocy' is used to describe 'power' or 'energy' required for operation.