And that can happen out of nowhere and a person who is abandoned is left alone without realizing that

The word abandon means to leave everything and go somewhere else

Abandon is when you give up on something and completely cut it off your life. For example, Her parents abandoned her after she fell pregnant at University. Feel free to message me should you require any further assistance.

The given definitions work well when the word is used as a verb. When used as a noun, it can mean "in a completely uncontrolled way." (eg: The young people in the club were dancing with abandon.)

Abandon means you no longer look after or support someone/something, basically you give up on them completely. Example- After our argument he completely abandoned me.