Sentence:  Leaving the theatre after the performance , I had a flash of intuition that life , after all ( as Rilke said ) , is just a search for the nonexistent cup of hot coffee , and that this unpretentious , moving , clever , <WSD>bitter</WSD> slice of life was the greatest thing to happen to the American theatre since Brooks Atkinson retired . 
Meaning of the word marked with <WSD> tags:  harsh or corrosive in tone