adventitiously
Definitions
In a way that happens by chance rather than design or inherent nature.
In a manner that is added from an external source or is not essential.
Examples
The discovery of the rare mineral occurred adventitiously while the team was surveying the area for water sources.
He adventitiously stumbled upon the solution to the complex equation while doodling in his notebook.
The two long-lost friends met adventitiously at a crowded airport terminal halfway across the world.
Synonyms
accidentally fortuitously incidentally chance casually unintentionally serendipitously
Antonyms
intentionally deliberately purposely designedly planned calculatedly willfully