This is the 11485th most frequent French word.
retomber
"Retomber" means "to fall again" or "to subside."
Here, 'retombent' (fall back) is used literally to describe an action of falling again.
Les feuilles mortes retombent au sol chaque automne.
The dead leaves fall back to the ground every autumn.
In this sentence, 'retomber' (fall back into) refers to the figurative action of reverting to a previous state or condition.
Il est facile de retomber dans ses anciennes habitudes.
It is easy to fall back into old habits.
Here, 'retomber' (fall back) is used to describe a return to a previous state of calmness or inactivity.