Matter is a type of Trouble. Trouble is related to Situation. Situation is related to Danger. 
Priority is related to Important. Important is similar to Burning. Refuse can be used for Burning. Refuse is a different concept from Want. 
Matter --IsA--> Trouble <--RelatedTo--> Situation <--RelatedTo--> Danger 
Priority <--RelatedTo--> Important <--SimilarTo--> Burning <--UsedFor-- Refuse <--DistinctFrom--> Want 