〜ともなく／〜ともなしに

Meaning

Describes doing an action vaguely, without a clear intention to do so. Often takes the form of repeating the same verb, as in 「見るともなく見る」 (to look without really looking).

Examples

見るともなくテレビを眺めていたら、知人が映っていた。 I was watching TV without really paying attention when I saw someone I knew on screen.
どこからともなく、花の香りが漂ってきた。 The scent of flowers drifted in from somewhere.