- 1a sudden steep fall or drop; a situation where something suddenly becomes worse or begins to fail Oil prices took a nosedive in the crisis. These policies have sent the construction industry into an abrupt nosedive. (figurative) Her spirits took a sudden nosedive after her husband's death. Stock markets have crashed in the biggest nosedive this century.
- 2a sudden sharp fall of an aircraft toward the ground with its front part pointing down The pilot put the plane into a nosedive.