Protect is the opposite of Harm. Harm is related to Danger. Danger is related to Warning. Warning is related to Hazard. 
Bicycle is a type of Toy. Toy is related to Baby. Baby is related to Nest. Nest is related to Bee. 
Protect <--Antonym--> Harm <--RelatedTo--> Danger <--RelatedTo--> Warning <--RelatedTo--> Hazard 
Bicycle --IsA--> Toy <--RelatedTo--> Baby <--RelatedTo--> Nest <--RelatedTo--> Bee 