narwhal tusk

noun

1. The long, spiral tooth (an elongated canine tooth) of a narwhal, a whale found in Arctic seas.

   B2

   countable

   • "The museum displayed a rare narwhal tusk in its Arctic exhibit."A2
   • "A narwhal tusk can grow up to three meters long."B2
   • "Some scientists believe the narwhal tusk functions as a highly sensitive sensory organ."C1