Dreaming of rook means that some of your friends fail to resolve their necessities of life. Dreaming of a dead rook means illness or death.
Dream dictionary: Rook dream meanings
(Carrion crow | Crow | Raven) Capturing a rook in a dream means receiving an inheritance, or it could mean presenting the truth before a jury in a court of justice that will be refuted, then presenting the judge with a false version that will be accepted. A rook in a dream also represents a highway robbery. (Also see Crow)
To see a rook means that business will be finished properly.
(Carrion crow | Crow | Hooded crow | Rook) In a dream, a raven represents a high ranking man, a forbearing and a patient person, or a strong and a well feared person. (Also see Crow | Rook)
…Dreaming of rooks, denotes that while your friends are true, they will not afford you the pleasure and contentment for which you long, as your thoughts and tastes will outstrip their humble conception of life. A dead rook, denotes sickness or death in your immediate future….