Emphasize is a synonym of Stress. Stress is related to Strain. Strain is a synonym of Extend. 
Drown is a synonym of Flood. Flood is a type of Flow. Flow is a synonym of Hang. Hang is the opposite of Lay. 
Emphasize <--Synonym--> Stress <--RelatedTo--> Strain <--Synonym--> Extend 
Drown <--Synonym--> Flood --IsA--> Flow <--Synonym--> Hang <--Antonym--> Lay 