This is the 2371st most frequent Polish word.
zaginęła
"Zaginęła" means "went missing" or "disappeared."
Here, 'zaginęła' is in reference to the missing book, showing its application in contexts of losing objects.
Jej ulubiona książka zaginęła w przeprowadzce.
Her favorite book was lost in the move.
Here, 'zaginęła' describes something forgotten or no longer remembered.
Kiedyś widziałem tę ulicę, ale jej nazwa zaginęła w mojej pamięci.
I once saw that street, but its name has vanished from my memory.
In this case, 'zaginęła' refers to a missing phenomenon that did not occur as expected.