I was watching a TV show, called Lost. And then a new character appeared,
Desmond Hume. I really liked the name Desmond as for me it sounds strong. So I thought "I should base my nickname on that". After many possible variations in my head and typing them in Google Translate (translating from Latin to English), I came up with "Dissimu". It was translated as "conceal", "dissemble". I like stealthy, secret things, so such a nickname was a true masterpiece for me.
I used Dissimu for a long while and I am still using it often. However, a few times someone called me shortly "Diss". I didn't like the sound of it too much, "Dess" sounded better me. Also, as I checked in the translator, the word "Dessimu" meant nothing. That said, I made myself a new, clean nickname with a possibility to make a history about this word. This is how I came up with my nickname.
I really like pirates, stories of treasure hunts and sea battles, mythology about sea monsters and so on. So I decided to associate "Dessimu" with a pirate. I think the name fits. And I love it.