Average is related to Amount. Amount is a synonym of Come. 
Fatigue is similar to Drain. Drain is related to Waste. Waste is related to Steam. Steam is related to Phase. 
Average <--RelatedTo--> Amount <--Synonym--> Come 
Fatigue <--SimilarTo--> Drain <--RelatedTo--> Waste <--RelatedTo--> Steam <--RelatedTo--> Phase 