Introducing a different topic.

synonyms: apropos, by the bye, incidentally.

Roget 9: relatively etc. adj.; pertinently etc. 23.    thereof; as to, as for, as respects, as regards; about; concerning etc. v.; anent; relating to, as relates to; with relation, with reference to, with respect to, with regard to; in respect of; while speaking of, a propos of [Fr.]; in connection with; by the way, by the by; whereas; for as much as, in as much as; in point of, as far as; on the part of, on the score of; quoad hoc [Lat.]; pro re nata [Lat.]; under the head of etc. (class) 75, of; in the matter of, in re.    ... show more

Roget 10: parenthetically etc. adj.; by the way, by the by; en passant [Fr.], incidentally; irrespectively etc. adj.; without reference to, without regard to; in the abstract etc. 87; a se.    ... show more

Roget 134: opportunely etc. adj.; in proper course, in due course, in proper season, in due season, in proper time, in due time; for the nonce; in the nick of time, in the fullness of time; all in good time; just in time, at the eleventh hour, now or never.    by the way, by the by; en passant [Fr.], a propos [Fr.]; pro re nata [Lat.], pro hac vice [Lat.]; par parenthese [Fr.], parenthetically, by way of parenthesis, incidentally; while speaking of, while on the subject; extempore; on the spur of the moment, on the spur of the occasion; on the spot etc. (early) 132.    ... show more

Roget 270: from hand to hand, from pillar to post.    on the way, by the way; on the road, on the wing, under way, in transit, on course; as one goes; in transitu [Lat.], en route, chemin faisant [Fr.], en passant [Fr.], in mid progress, in mid course.    ... show more

Roget 621: randomly, by chance, fortuitously; unpredictably, unforeseeably; casually etc. 156; unintentionally etc. adj.; unwittingly.    en passant [Fr.], by the way, incidentally; as it may happen; at random, at a venture, at haphazard.    ... show more