Dispute is related to Domestic. Domestic is a synonym of Comfortable. 
Toilet can be used for Waste. Waste is related to Pollution. Pollution is the opposite of Conservation. Conservation is related to Save. 
Dispute <--RelatedTo--> Domestic <--Synonym--> Comfortable 
Toilet --UsedFor--> Waste <--RelatedTo--> Pollution <--Antonym--> Conservation <--RelatedTo--> Save 