The Quenya word for hand is má. The dual plural meaning "a pair of hands" is mát. Also, camba means "the whole hand, but as flexed, with fingers more or less closed, cupped, in the attitude of receiving or holding."
The Sindarin word for hand is cam. Also, mâb means "a hand-full, complete hand."
In addition, Tolkien has completely different words for the left hand and the right hand. I don't think I'll go there.