According to Wiktionary:
1. An unsought, unintended, and/or unexpected, but fortunate, discovery and/or learning experience that happens by accident.
2. A combination of events which are not individually beneficial, but occurring together produce a good or wonderful outcome.
Serendipity is when you find things you weren't looking for because finding what you're looking for is so damn difficult. - Erin McKean
According to Dictionary.com
1. An aptitude for making desirable discoveries by accident.
2. Good fortune; luck:
"the serendipity of getting the first job she applied for."
According to Urban Dictionary:
1. A very good coincidence, often leading to something really awesome.
It was serendipity that I put one quarter in the gumball machine and three came out. :-)
2. A fortunate accident.
I got lost and found a bag of money, what a serendipity.
3. The action of making happy discoveries, by accidents or sagacity, of something not initially in quest of.
'I lost a needle in a hay stack last week, however whilst looking for it I found the farmer's daughter' - I had to consider this (as she was pretty and willing) a stroke of serendipity.
4. Lucky chance
Them falling in love was purely serendipity.
5. Something pleasant or useful found while looking for something else. Inspired by a Persian fairy story, "The Three Princes of Serendip".
I initially wanted to date Moira, but she turned out to be an awful bore and she snorted when she laughed, which I can't stand. She did however get me in touch with a car dealer who makes really cool custom cars, top quality and dirt cheap, three of which I bought within a year. That was a real piece of serendipity.
6. Finding the most amazing guy in the world while he is doing laundry on your hall. aka a happy accident or coincidence. Everything happens for a reason.
As I saw Kevin walking down the hall with his laundry I knew I had to make him mine. Turns out he likes me too and everything falls into place perfectly. Call it serendipity? Or fate?