The term 'parenthetically' refers to a type of speech or writing in which additional information is provided in parentheses. The crossword solutions INCIDENTALLY (12 letters), BYTHEWAY (8 letters), ASANASIDE (9 letters) and INANASIDE (9 letters) all refer to similar concepts, as they are all phrases used to introduce an aside or additional information. These phrases are often used to provide extra context or to make a comment that is not directly related to the main topic.