A cagoule, cagoul, kagoule or kagool (from the French cagoule meaning hood) is the British English term for a lightweight (usually without lining), weatherproof raincoat or anorak with a hood, which often comes in knee-length. The American English equivalent is poncho.
A cagoule which can be rolled up into a very compact package and carried in a bag or pocket was invented by Noel Bibby of Peter Storm Ltd. in the early 1960s. It has an integral hood, elasticated or drawstring cuffs, and a few poppers (snap fasteners) or a short zip at the neck. It does not open fully at the front and must be pulled on over the head. In some versions, when rolled up, the hood or front pocket doubles as a bag into which the rest of the coat is pushed. It became very popular in the United Kingdom during the 1970s, going by such trademarks as Pack-a-Mac & "Cag in a Bag".