Serendipitous means happening by a happy accident. A serendipitous discovery, entirely serendipitous, a serendipitous meeting.
The word was coined in 1754 from a Persian tale about three princes of Serendip who kept finding things they were not looking for. Penicillin is the standard example, and a great deal of science is more serendipitous than the papers admit.
1adjectiveserendipitousHappening by a happy accident.
“Our meeting was serendipitous: we sat next to each other on a delayed train.”
serendipitous is a quality.
From serendipity + -ous.
Etymology from Wiktionary, CC BY-SA