In the book “Ghost” what is castle fear ?

Explanation:

Castle Crenshaw, or Ghost, as he has nicknamed himself, begins his story ... But five pages into “Ghost,” Jason Reynolds's new middle-grade novel, ... At school, he gets in trouble and struggles to contain his fear and anger.

In order to interprete literature the cultural context is fundamental because it is likely to have influence on the narrative, that is, the story may be based on tipical problems or events which took place at the time the author wrote the it, such as a revolution or a war. Besides, the biography of the author may also play a key role to interprete a story since certain authors tend to write stories invoking personal experiences, such as discrimination because of racism, for example. Finally, quotes from the text are much more significant, because they can be the own words of the characters, or the author himself, so they should be analized aiming to undestand the intention of the author with his story.

So, I must say that your own comment on the text is the option which is not an acceptable form to evidence yout interpretation.