Noun
finalizer (plural finalizers)
(programming) A function that runs when an object is garbage collected, similar to a destructor.
A Java object's finalizer is invoked asynchronously some time after it has been accessed for the last time and before it is deallocated. Source: Internet
A finalizer is needed by only objects that must guarantee some cleanup of the object state before deallocating, typically releasing resources external to the JVM. Source: Internet