Laughter is related to Smile. Smile is related to Lip. 
Suitable is a synonym of Just. Just is a synonym of Due. Due is related to Owe. Owe is related to Tax. 
Laughter <--RelatedTo--> Smile <--RelatedTo--> Lip 
Suitable <--Synonym--> Just <--Synonym--> Due <--RelatedTo--> Owe <--RelatedTo--> Tax 