Defeat is the opposite of Fall. Fall is related to Dead. Dead is related to Die. Die is related to Death. 
Drift is a type of Float. Drift is a type of Vary. Vary is etymologically related to Various. Various is derived from Variety. 
Defeat <--Antonym--> Fall <--RelatedTo--> Dead <--RelatedTo--> Die <--RelatedTo--> Death 
Float <--IsA-- Drift --IsA--> Vary --EtymologicallyRelatedTo--> Various --DerivedFrom--> Variety 