Definition of crown of thorns in English:

crown of thorns

noun

  • 1A large spiky starfish of the tropical Indo-Pacific, feeding on coral and sometimes causing great damage to reefs.

    • ‘They could have chosen the ugly and destructive crown of thorns starfish instead.’
    • ‘I'm a film maker, I've been diving the reef for 37 years now and the last 18 months I've spent a lot of time on it filming crown of thorns.’
    • ‘It looks an impossible job when a soft-bellied gastropod like the triton tries to demolish a spiky crown of thorns starfish.’
    • ‘Nudibranchs dotted the undersides of the coral and a spiny crown of thorns sea star moved slowly underneath a plate coral.’
    • ‘The crown of thorns starfish, one of the largest of the sea star group, measures approximately 45 cm across its seven to seventeen arms.’
  • 2A Madagascan shrub of the spurge family, with bright red flowers and many slender thorns. It is a popular houseplant and is sometimes used for hedges in the tropics.

    • ‘Hat rack cactii and pencil bush are both euphorbias, as is crown of thorns, so I'd consult a doctor about those, too.’
    1. 2.1 Any of a number of other thorny plants, especially Christ's thorn.
      • ‘In medieval times it was the belief that Jesus crown of thorns was blackberry brambles.’
      • ‘Some believers think the crown of thorns was made of this type of tumbleweed.’
      • ‘The evergreen holly was worshiped as a promise of the sun's return, and some say that Christ's crown of thorns was made of holly.’

Origin

By association with Christ's crown of thorns.