Ralph Waldo —, US poet who authored 1836 essay Nature (7)
I believe the answer is:
emerson
(Other definitions for emerson that I've seen before include "American writer, 1803-82" , "Ralph Waldo --, US poet" , "Ralph Waldo . . . . . . ., wrote The American Scholar" , "Ralph Waldo ......., 19th century American transcendentalist" , "American poet and philosopher, d. 1882" .)