This is an English locational surname which is also recorded in Ireland. It originates from one of the many places called Westbrook, to be found for instance in the counties of Berkshire, Dorset, Buckingham, Hertford, Surrey and the Isle of Wight. The name means 'The village built to the west of the brook'. In pre 7th century Olde English brook, or rather broc, did not mean just a stream. It was a generic word which had different meanings in different parts of the country, and the best that one can is that it always meant water. Curiously whilst there are almost as many places called Eastbrook and Northbrook, there are only two called Southbrook. Locational surnames are generally 'from' names. That is to say names given to people after they left their original homes for whatever reason and moved somewhere else. The easiest way to identify such strangers was to call them by the name of the place from whence they came. Interestingly many of the villages called Westbrook seem to have disappeared and are now only recorded as 'localities,' if they appear on the maps at all. In some instances this may have been because of the draining of the countryside in the 16th to 18th centuries, and the change to sheep farming, which lead to the abandonment of many small places. The ealiest known recording of the surname is probably that of Richard de Westbroc, in the Hundred Rolls of Surrey in the year 1273.