Cell is related to Box. Box is related to Pack. Pack is a type of Seal. 
Casual is the opposite of Formal. Formal is related to Dress. Dress is related to General. 
Cell <--RelatedTo--> Box <--RelatedTo--> Pack --IsA--> Seal 
Casual <--Antonym--> Formal <--RelatedTo--> Dress <--RelatedTo--> General 