I think this is a very informative lecture and a great introduction to German Romantism. As a native German speaker, I have one small but important correction to make, though: The word "Sehnsucht" is a compound noun which is composed of the two words "sehnen" (not "sehen"!!!) and "Sucht. "Sehnen" is the German word for "to yearn" and "Sucht", as stated, means Addiction. The explanations delivered by Jason Lieblang are all correct, however, they do not make any sense if you derive "Sehnsucht" from "sehen" (to see). Just to make sure, I looked up both "sehnen" and "Sucht" in the etymological Duden. The word "sensuht" was already around in Middle High German (that is: in the Middle Ages) which means that the original meaning of Sucht, a derivation of "siech" (=to be sick) schould probably apply. "Suht" was mainly used to describe a pathological yearning for something, there is still a destinction to be made between the way we are using the word "addiction" today, where we mainly think of drugs and the original. "Sucht" was mainly applied to emotions that one seeks, vices and also sin. Hence we have the words "Herrschsucht" (bossiness, literally: craving to lead), "Gefallsucht" (craving for admiration) or Selbstsucht (selfishness, literally: craving for the own person). I think it is remarkable that the words "to yearn" and "to crave" are pretty similar in their meaning. In German, it is pretty much the same with "sehnen" and "Sucht" which is why it to me, at first glance and before looking it up, it appeared to be just to be a compound of two words with the same meaning to reinforce the profoundness of its meaning.