Wal ‧ lis, Sir Barnes /ˈwɒləs, ˈwɒlɪs $ ˈwɑː-, bɑːnz $ bɑːrnz/ BrE AmE
(1887–1979) a British engineer and inventor. He is known especially for developing the BOUNCING BOMB , which was used to destroy ↑ dam s (=large walls built across rivers) in Germany during World War II. The story of how he invented this bomb is told in the film The Dam Busters .