Diagnose is related to Condition. Condition is related to Silence. Silence is the opposite of Talk. Talk is a different concept from Quiet. 
Crowd is related to Tight. Tight is the opposite of Lose. Lose is the opposite of Gather. Gather is a synonym of Harvest. 
Diagnose <--RelatedTo--> Condition <--RelatedTo--> Silence <--Antonym--> Talk <--DistinctFrom--> Quiet 
Crowd <--RelatedTo--> Tight <--Antonym--> Lose <--Antonym--> Gather <--Synonym--> Harvest 