Noun
parliamentary train (plural parliamentary trains)
(rail transport, UK, chiefly historical) Originally a requirement in the Railway Regulation Act 1844 for railways to run at least one train a day each way, at a cost to passengers of no more than one penny a mile, on every railway line in the country. Presently the term is used for passenger trains that serve a line or station only once a day or week to avoid the cost of applying for closure.