serendipity

/ˌsɛ.ɹən.ˈdɪ.pɪ.ti/

meaning in plain English

Finding something good or nice by pure luck when you weren’t even looking for it.

Picture finding a $20 bill on the sidewalk—serendipity: lucky surprise you weren’t hunting for.

for example

I found my dream job by pure serendipity when a friend mentioned it in passing.

Remember that time you reached for a random book on the shelf just to flip through it, and stumbled upon the exact page that solved your work problem? That’s serendipity—when life hands you a perfect solution you never knew you needed.