Rain is related to Hurricane. Hurricane is a type of Single. Single is related to Unit. Unit is etymologically related to Unity. 
Leather is related to Hide. Hide is the opposite of Found. Found is related to Discovery. Discovery is related to Find. 
Rain <--RelatedTo--> Hurricane --IsA--> Single <--RelatedTo--> Unit --EtymologicallyRelatedTo--> Unity 
Leather <--RelatedTo--> Hide <--Antonym--> Found <--RelatedTo--> Discovery <--RelatedTo--> Find 