This is the 475th most frequent Czech word.
ruce
"Ruce" means "hands" in English.
In this sentence, 'ruce' refers to hands as a body part, used to describe an action involving them.
Dejte si ruce na hlavu.
Put your hands on your head.
Here, 'ruce' metaphorically refers to hands, emphasizing being occupied or busy.
Mám plné ruce práce.
I have my hands full of work.
In this case, 'ruče' is part of 'náruče', meaning arms, often used to describe an embrace or holding someone.