Obvious is related to Plain. Plain is a synonym of Naked. Naked is related to Birthday. Birthday is the opposite of Half. 
Naked is related to Club. Club is related to Weapon. Weapon is a type of Artifact. 
Obvious <--RelatedTo--> Plain <--Synonym--> Naked <--RelatedTo--> Birthday <--Antonym--> Half 
Naked <--RelatedTo--> Club <--RelatedTo--> Weapon --IsA--> Artifact 