Shrink is a synonym of Decrease. Decline is a type of Decrease. Decline is the opposite of Rally. Rally is etymologically related to Rail. 
Dirt is related to Seed. Seed is related to Stone. Stone is related to Weed. 
Shrink <--Synonym--> Decrease <--IsA-- Decline <--Antonym--> Rally --EtymologicallyRelatedTo--> Rail 
Dirt <--RelatedTo--> Seed <--RelatedTo--> Stone <--RelatedTo--> Weed 