Synonyms and related words :
a propos, accidental, aimless, apropos, apropos of, by the by, by-the-way, casual, desultory, deviative, digressive, discursive, en passant, episodic, excursive, for example, in passing, incidental, incidentally, loose, maundering, occasional, par exemple, parenthetical, parenthetically, rambling, roving, speaking of, wandering,