This is the 8403rd most frequent French word.
abîmer
To damage or ruin.
Here, 'abîmer' means 'to damage' or 'to spoil' something, used in a warning context to handle the books carefully.
Il ne faut pas abîmer les livres en les manipulant trop brusquement.
You mustn't damage the books by handling them too roughly.
In this case, 'abîmer' refers to physical damage caused by external factors.
La pluie a abîmé la peinture de la voiture.
The rain damaged the paint on the car.
'Abîmer' is used to describe the deterioration or wear over time affecting the materials.