Sentence:  It is preferable that the <WSD>zeroah</WSD> (roasted bone) and the beitzah (roasted egg) which are placed on the Seder plate (k'arah) be prepared before Shabbos. 
Meaning of the word marked with <WSD> tags:  The bone of a lamb shank, laid on a platter as one of five symbolic foods at Passover, representing the arm of God, hence the Messiah.