Tighten is a synonym of Reduce. Reduce is related to Amount. Amount is related to Degree. 
Winter is related to Bear. Bear is related to Cousin. Cousin is related to Garlic. 
Tighten <--Synonym--> Reduce <--RelatedTo--> Amount <--RelatedTo--> Degree 
Winter <--RelatedTo--> Bear <--RelatedTo--> Cousin <--RelatedTo--> Garlic 