Significance is a synonym of Import. Important is derived from Import. Important is similar to Strategic. 
Spending is the opposite of Conservation. Conservation is the opposite of Pollution. Pollution is related to Waste. Waste is a different concept from Saving. 
Significance <--Synonym--> Import <--DerivedFrom-- Important <--SimilarTo--> Strategic 
Spending <--Antonym--> Conservation <--Antonym--> Pollution <--RelatedTo--> Waste <--DistinctFrom--> Saving 