Definition of dragon's teeth in English:

dragon's teeth

plural noun

British
informal
  • Concrete obstacles pointing upwards from the ground in rows, used against tanks in the Second World War.

    • ‘When I was told to attack the Siegfried Line, I was given a 1: 100K map and three aerial photos of the pillboxes and dragon's teeth complex in my assigned sector and told to be ready at 4 A.M. but not to move until ordered.’
    • ‘Chairman Paul Melhuish said: ‘We looked at the possibility of fitting dragon's teeth or a barrier that horses and pedestrians could easily step over but would prevent other traffic from using it.’’

Origin

With allusion to the teeth of the dragon killed by Cadmus.