Sentence:  So he flew down and got that acorn, and fetched it up and dropped it in, and was just tilting his head back, with the <WSD>heavenliest</WSD> smile on his face, when all of a sudden he was paralyzed into a listening attitude and that smile faded gradually out of his countenance like breath off′n a razor, and the queerest look of surprise took its place. 
Meaning of the word marked with <WSD> tags:  Strongly or sublimely beautiful or pleasurable.