Tunnel is related to Hole. Hole can be used for Entry. Entry is a synonym of Introduction. Introduction is related to Card. 
Rest is etymologically related to Arrest. Rest is related to Ease. Ease is a synonym of Calm. 
Tunnel <--RelatedTo--> Hole --UsedFor--> Entry <--Synonym--> Introduction <--RelatedTo--> Card 
Arrest <--EtymologicallyRelatedTo-- Rest <--RelatedTo--> Ease <--Synonym--> Calm 