Rear is the opposite of Front. Front is related to Back. Back is a synonym of Previous. 
Iron is related to Hard. Hard is related to Good. Good is related to Health. Health is related to Evaluation. 
Rear <--Antonym--> Front <--RelatedTo--> Back <--Synonym--> Previous 
Iron <--RelatedTo--> Hard <--RelatedTo--> Good <--RelatedTo--> Health <--RelatedTo--> Evaluation 