The dictionary defines 'tradition' as the handing down of statements, beliefs, legends, customs, information, ways of thinking, practices etc., from generation to generation.
The Catholic Church defines tradition as "revealed truths apart from those contained in the Bible"... established by Church practice over time, they are the living 'magisterium' (teaching authority); truth, communicated to the church through the apostles, of whom the Pope is the direct spiritual descendent.
A simpler definition, provided by an anonymous contributor to a Christian Discussion forum, is that it's 'man-made claptrap'...
... a bit like Bible Covers.