free fall

Từ điển WordNet v3.1 - WordNet Dictionary

noun

1. the ideal falling motion of something subject only to a gravitational field
• Hypernyms:
drop, fall
2. a sudden sharp decrease in some quantity
- a drop of 57 points on the Dow Jones index
- there was a drop in pressure in the pulmonary artery
- a dip in prices
- when that became known the price of their stock went into free fall
• Syn:
drop, dip, fall
• Derivationally related forms:
fall (for: fall), drop (for: drop)
• Hypernyms:
decrease, decrement
• Hyponyms:
correction, voltage drop