Series is a type of Contest. Series is a synonym of Line. Line is related to Slope. Slope is related to Surface. 
Sophisticated is the opposite of Plain. Plain is related to Special. Special is related to Suite. 
Contest <--IsA-- Series <--Synonym--> Line <--RelatedTo--> Slope <--RelatedTo--> Surface 
Sophisticated <--Antonym--> Plain <--RelatedTo--> Special <--RelatedTo--> Suite 