This is the 9555th most frequent French word.
dégringolent
"Collapse" or "tumble down rapidly."
The word 'dégringolent' describes the action of descending rapidly and somewhat chaotically, which applies to leaves falling.
Les feuilles dégringolent des arbres en automne.
The leaves tumble down from the trees in autumn.
Here, 'dégringolent' metaphorically conveys a rapid and significant decrease in prices.
Après la crise, les prix dégringolent partout.
After the crisis, prices tumble everywhere.
This usage refers to the unsteady and quick descent of people down the stairs, potentially in an uncontrolled manner.