Safe is related to Steel. Steel is related to Concrete. 
Small is related to Dot. Dot is related to Line. Line is a synonym of Trace. Trace is a synonym of Describe. 
Safe <--RelatedTo--> Steel <--RelatedTo--> Concrete 
Small <--RelatedTo--> Dot <--RelatedTo--> Line <--Synonym--> Trace <--Synonym--> Describe 