Birthday is related to Thing. Thing is related to Swim. Swim is related to Front. 
Matter is a synonym of Thing. Thing is a synonym of Affair. Affair is the opposite of Loyal. 
Birthday <--RelatedTo--> Thing <--RelatedTo--> Swim <--RelatedTo--> Front 
Matter <--Synonym--> Thing <--Synonym--> Affair <--Antonym--> Loyal 