Webster Dictionary(0.00 / 0 votes)Rate this definition: 1  Cousin(noun) one collaterally related more remotely than a brother or sister; especially, the son or daughter of an uncle or aunt. 2  Cousin(noun) a title formerly given by a king to a nobleman, particularly to those of the council. 3  Cousin(noun) allied; akin.
As everyone has explained MSMQ is used as a queue for messages. Messages can be wrapper for actual data, object and anything that you can serialize and send across the wire. MSMQ has it's own limitations. MSMQ 1.0 and MSMQ 2.0 had a 4MB message limit. This restriction was lifted off with MSMQ 3.0.
RabbitMQ is a messaging broker - an intermediary for messaging. It gives your applications a common platform to send and receive messages, and your messages a safe place to live until received.