looking on; remaining a spectator
behaving outrageously as though there were no one around; acting without consideration for others; arrogance; audacity; insolence
interception; monitoring; tapping
listening (to a lecture, hearing, parliament session, etc.); attending (without participating); sitting in (e.g. on a meeting); observing
neighborhood; neighbourhood; vicinity; neighborhood; neighbourhood
collateral family; subsidiary line; affiliate; coset
visitor's gallery; seats for the public
observer; spectator (e.g. in court); (member of the) public; visitor; audience; gallery
branch (of a river); tributary; branch; offshoot; something not mainstream
supporting evidence; corroboration
underline; side line (equivalent to underlining in vertically written text)
side of the road; roadside
marks or dots written alongside a word to indicate stress or draw the reader's attention; emphasis mark; guiding marks written beside kanji to facilitate reading of kanbun
utter stranger; mere passerby; outsider
hands-off; indifferent; spectatorial
digression; dicta; dictums
subtitle (e.g. of a book)
citing copious references
looking on with folded arms (with one's hands in one's sleeves); remaining a passive onlooker
marginal notes; side notes; gloss
collateral relation by blood
looking from the side; looking aside