Incidentally

amúgy

(by the way — see also by the way)

egyébként

(by the way — see also by the way)

futólag

(in an incidental manner)

mellesleg

(by the way — see also by the way)

mellékesen

(in an incidental manner)

véletlenül

(without looking for something/somebody)

érintőleg

(in an incidental manner)

érintőlegesen

(in an incidental manner)