Cluster is a synonym of Bunch. Bunch is related to Crowd. Crowd is related to Collective. 
Wish is a type of Preference. Wish is related to Bless. Bless is related to Phrase. Phrase is similar to Expression. 
Cluster <--Synonym--> Bunch <--RelatedTo--> Crowd <--RelatedTo--> Collective 
Preference <--IsA-- Wish <--RelatedTo--> Bless <--RelatedTo--> Phrase <--SimilarTo--> Expression 