ETYM Icel. bâra wave: cf. German empor upwards, Old High Germ. bor height, burren to lift, perh. allied to AS. beran, Eng. bear.
(Homonym: boar, Boer, boor).
1. Diameter of a tube or gun barrel; SYN. caliber, calibre.
2. A person who evokes boredom; SYN. dullard.
3. (Mining terms) A hole or passage made by a drill; usually made for exploratory purposes; SYN. bore-hole, drill hole.

1. To cause to be bored; SYN. tire.
2. To drill a hole into; SYN. drill.
tidal flow of water up estuaries
wall of water advancing up narrow estuary at certain tides.

In music, the internal diameter of tubing of a brass or woodwind instrument, as in “wide bore”, “narrow bore”.

Surge of tidal water up an estuary or a river, caused by the funneling of the rising tide by a narrowing river mouth. A very high tide, possibly fanned by wind, may build up when it is held back by a river current in the river mouth. The result is a broken wave, a meter or a few feet high, that rushes upstream.
Famous bores are found in the rivers Severn (England), Seine (France), Hooghly (India), and Chiang Jiang (China), where bores of over 4 m/13 ft have been reported.