Incidentally is an adverb that means 'by chance' or 'in passing'. Obiter is a 6-letter synonym for incidentally, meaning 'in passing'. CASUALLY is an 8-letter synonym for incidentally, meaning 'without much thought or concern'. PARENTHETICALLY is a 15-letter synonym for incidentally, meaning 'as an aside'. FORTUITOUSLY is a 12-letter synonym for incidentally, meaning 'happening by chance'. ACCIDENTALLY is a 12-letter synonym for incidentally, meaning 'happening by chance'. UNEXPECTEDLY is a 12-letter synonym for incidentally, meaning 'without warning'. SAY is a 3-letter synonym for incidentally, meaning 'to express in words'. Bytheby is a 7-letter synonym for incidentally, meaning 'by the way'. Bythebye is an 8-letter synonym for incidentally, meaning 'by the way'. Bytheway is an 8-letter synonym for incidentally, meaning 'by the way'. Inpassing is a 9-letter synonym for incidentally, meaning 'in passing'. Ohbytheway is a 10-letter synonym for incidentally, meaning 'by the way'.