Return is a synonym of Fall. Fall is related to Stumble. 
Turn is related to Take. Take is the opposite of Add. Add is a synonym of Contribute. Contributor is derived from Contribute. 
Return <--Synonym--> Fall <--RelatedTo--> Stumble 
Turn <--RelatedTo--> Take <--Antonym--> Add <--Synonym--> Contribute <--DerivedFrom-- Contributor 