Anyway - a place I often start is with a dictionary - to at least see where a word came from. Even if it is being used differently or incorrectly or it has changed over time. So - I found this definition, which fits with what I've been experiencing:
World English DictionaryThen, for fun, and because I was following the root of the word, the origins, I went down that path and discovered synchronous. There is the synchronous engine, which is (in very basic laymen's terms from the different sources I've read) a spinning rotor with coils and alternating current - the coils pass magnets at the same rate as the current and it creates a rotating magnetic field.
an apparently meaningful coincidence in time of two or more similar or identical events that are causally unrelated
So - synchronicity and synchronous motors: energy, in the field, laws of attraction and what goes out/comes back, it's "in the air." So part of catching what is there is being aware. Then there are other theories about putting out into the universe what you want to get back, or putting in effort gives you results, and so on.
Leading back to, for me, what has come up in one part of my life appears in another place. Unrelated. Sometimes unexpected - usually unexpected. Yes - I also know that, for example, if you're thinking about buying a new car, suddenly the ones you've targeted as possibilities are showing up everywhere on the road; or another example: quick, don't think of green elephants - and now you are. I know. There is that.
And - things have been popping up.
My best friend from childhood, whom I hadn't seen for 30 years, sending an email about meeting up right when I was writing a story for my memoir that was about the two of us. Then her talking about a disease, which I talked about with my partner the next day, which came up on a program my partner was watching that night (it's a rare disease). And other instances like that. I have a question about something and look it up - and there it is in an article in my email the next day. Or I'm talking with my partner about some news story and she just had a similar experience.
Or maybe I'm just in a time of being more mindful and more aware and so I catch it. Like the red and green spots in the motor.
Something to think about.