Unit is etymologically related to Unite. Unit is related to Age. Age is related to Adult. Adult is a type of Animal. 
Bat is related to Sport. Sport is related to Ball. Ball is related to Found. Found is related to Reward. 
Unite <--EtymologicallyRelatedTo-- Unit <--RelatedTo--> Age <--RelatedTo--> Adult --IsA--> Animal 
Bat <--RelatedTo--> Sport <--RelatedTo--> Ball <--RelatedTo--> Found <--RelatedTo--> Reward 