* Swerte ng pagkakataon (literally: "luck of the opportunity")
* Hindi inaasahan (literally: "not expected")
* Kakaiba at nakakagulat na pangyayari (literally: "strange and surprising event")
* Di-sinasadyang pagkakatuklas (literally: "unintentional discovery")
The best translation depends on the context and the specific nuance of "serendipity" you want to convey.
For example:
* "I found this amazing book by serendipity." can be translated as "Napagtanto kong nakita ang nakakamangha na libro na ito dahil sa swerte ng pagkakataon."
* "The serendipitous encounter led to a new friendship." can be translated as "Ang di-sinasadyang pagkikita ay humantong sa bagong pagkakaibigan."
Remember, it's important to consider the context and choose the phrase that best captures the meaning of serendipity.