BORE  , a high tidal

wave rushing up a narrow estuary or tidal river . The bore of the Severn is produced by a tide that rises 18 ft. in an hour and a half . This body of water becomes compressed in the narrowing funnel-shaped estuary, and heaped up into an advancing wave extending from bank to bank . The phenomenon is also particularly well illustrated in the Bay of Fundy . The origin of this word is doubtful, but it is usually referred to a Scandinavian word bara, a wave, billow . The other name by which the phenomenon is known, " eagre," is also of unknown origin . There is, of course, no connexion with " bore," to make a hole by piercing or drilling, which is a common Teutonic word, cf . Ger. bohren, the Indo-European root being seen in Lat. forare, to pierce, Gr . 4,apos, plough . For the making of deep holes for shafts, wells, &c., see BORING . The substantival use of this word is generally confined to the circular cavity of objects of tubular shape, particularly of a gun, hence the internal diameter of a gun, its " calibre " (see GuN) . A " bore " is also a tiresome, wearying person, particularly one who persistently harps on one subject, in or out of season, whatever interest his audience may take in it .

This has generally been taken to be merely a metaphorical use of " bore," to pierce . The earliest sense, however, in which it is found in

English (1766, in certain letters printed in Jesse's Life of George Selwyn) is that of ennui, and a French origin is suggested . The New English Dictionary conjectures a possible source in Fr. bourrer, to stuff, satiate .