They were sent for by the King and Queen.
Claudius and Gertrude set Rosencrantz and Guildenstern to spy on Hamlet to discover the cause of his apparent madness
He accuses Guildenstern of playing him like a recorder.
There is no specific meaning as Rosencrantz and Guildenstern explores so many different views. If you wanted a definitive meaning I guess it would be to demonstrate the absurdity of life.
Hamlet changes the letter going to the King of England to kill him when he gets there to say to kill the people who give you this letter,which were Rosencrantz and Guildenstern. So they were killed instead.
claudius
Claudius and Gertrude set Rosencrantz and Guildenstern to spy on Hamlet to discover the cause of his apparent madness
Rosencrantz and Guildenstern - both who end up dead.
He arranged to have them killed.
He accuses Guildenstern of playing him like a recorder.
castle
White Castle meat comes from slaughtered cows.
Rosencrantz and Guildenstern are Hamlet's childhood friends. Claudius sends them to spy on Hamlet.
from a castle
no
They must be brothers...? If not, good friends. They come as a pair throughout the whole play and even the names seem to go together as a pair.
rosencrantz and guildenstern
The royal couple are, in effect, recruiting Hamlet's old friends, Rosencrantz and Guildenstern, to spy on him for them.