This is the 606th most frequent Slovak word.
rúk
"Rúk" is the genitive plural form of "ruka," meaning "hands" in English.
Here, 'rúk' is in the plural genitive case to express possession or relation (belonging of hands to us).
Podali sme si ruky na znak dohody.
We shook hands as a sign of agreement.
In this sentence, 'rukami' is used to denote the instrumental case indicating the means by which the action is performed.
Rukami prestrihol povraz a oslobodil zajatca.
With his hands, he cut the rope and freed the prisoner.
Here, 'ruky' is accused to represent the anatomical part receiving the action.