Listener is the opposite of Speaker. Speaker is related to Leader. Leader is related to Elect. 
Gain is etymologically related to Wide. Gain is the opposite of Lose. Drop is a type of Lose. Drop is a synonym of Abandon. 
Listener <--Antonym--> Speaker <--RelatedTo--> Leader <--RelatedTo--> Elect 
Wide <--EtymologicallyRelatedTo-- Gain <--Antonym--> Lose <--IsA-- Drop <--Synonym--> Abandon 