To me “to publish” simply means to put your work in the world for strangers to read. You might do it yourself or someone might do it for you. A lot of people might read your work, or hardly anyone. Either way, when you publish you put yourself out there.
With that said, it’s like that moment in “Total Recall” (1990) when Quaid meets Kuato, the deformed humaniod who’s been under his brother’s shirt this whole time, conjoined to the dude’s stomach.
In this metaphor, you are the brother and your work is Kuato.
It’s this thing you’ve been keeping to yourself for a long-ass time. And then suddenly you open your shirt and–BLAAARGH. Your work might not be bad (or it might be) and people might not freak out (or they might). But that, in a nutshell, is how it feels to publish your writing.
p.s. If you haven’t read “We Can Remember it for You Wholesale” by Philip K. Dick, the short story upon which the movie is based, do so immediately.