Small is the opposite of Full. Full is a type of Beat. Beat is a synonym of Shell. Shell is related to Defense. 
Crush is a type of Crowd. Crush is related to Violent. Violent is related to Accident. 
Small <--Antonym--> Full --IsA--> Beat <--Synonym--> Shell <--RelatedTo--> Defense 
Crowd <--IsA-- Crush <--RelatedTo--> Violent <--RelatedTo--> Accident 