Both morn and morrow continue earlier Middle English morwen (the former through early contraction, the latter through regular reduction of -en). morrow (plural morrows) (archaic or poetic) The next or following day. Two men were walking in the street; one said to the other: “Upon the morrow I will sup with thee.” More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.