IPA: /ˌæd.vənˈtɪʃ.əs.li/
KK: /ædˌvɛntɪˈtɪʃəsli/
In a way that happens by chance or is not planned; occurring accidentally.
The findings were adventitiously discovered during the research process.
Adventitiously → It is formed from "adventitius" (from Latin, meaning accidental or happening by chance) and the suffix "-ly" (meaning in a manner). The word describes something that occurs by chance or accidentally.
Think of something happening 'by chance' — 'adventitiously' means occurring accidentally.