Knowledge is a synonym of Understanding. Understanding is related to Confusion. Confusion is a different concept from Sure. 
Stick is the opposite of Slip. Slip is related to Female. Female is a different concept from Male. Male is related to Guy. 
Knowledge <--Synonym--> Understanding <--RelatedTo--> Confusion <--DistinctFrom--> Sure 
Stick <--Antonym--> Slip <--RelatedTo--> Female <--DistinctFrom--> Male <--RelatedTo--> Guy 