Argument is a synonym of Debate. Debate is a synonym of Talk. Talk is related to Speak. 
Worried is related to Anxiety. Concern is a type of Anxiety. Concern is related to Matter. Matter is related to Rub. 
Argument <--Synonym--> Debate <--Synonym--> Talk <--RelatedTo--> Speak 
Worried <--RelatedTo--> Anxiety <--IsA-- Concern <--RelatedTo--> Matter <--RelatedTo--> Rub 