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Armstrong, et al. cite Ekwall,[1] who "derives this name from Welsh 'blaen' 'top'...and 'cog' 'cuckoo' to which was later added ON 'haugr' 'hill' ". However, they say that it is more probable that the final element "is the British plural inflexion (Welsh '-au', Cornish '-ow', Breton '-ou')." [2] So, ' hill of the cuckoo or cuckoos'.('ON' is Old Norse; 'British' is Common Brittonic).