His given name;
Jan Sauer is Ziggy's original name. It's pronouned, Yahn Sah-er. The name is Germanic in nature and ties in directly with the German theme of the game. Not only that, but Ziggy also has blonde hair and blue eyes. Perhaps the creators wanted Ziggy to appear German as well?
Origins
This is Ziggy's first given name. Jan actually originates from the name John. The English variations of the name are Johan, Jehan, Jen, and Jan. Jan is actually a common name in Germany. Going back to it's roots, John is a Biblical name (John the Baptist), and is the most common Christian first names. It's actual meaning is "Jehovah has favored", and "he was gracious".
The prefix "jan" is used in several words. It's actual meaning is "beginning". We see this in the month, January. Janus was an ancient god said to be the patron of beginnings and endings. He was shown as having two faces, one in the front and one in the back.
This origin of his name holds a lot of significance. Firstly, out of the main party members, Jan was the first one to be born. He's over a hundred years old. More importantly, Jan was the first character that chaos effected in order to change Wilhelm's plans.
In Xenosaga Pied Piper, Jan is rescued from death by a mysterious voice. The picture that accompanies the voice's dialogue is chaos' character art from Episode I, but blurred. He deliberately warns him not to chase after a shadow, and that he's needed in the future. Later, Wilhelm makes a comment that chaos was getting help from others in order to obstruct his plans.
I also felt like adding the tidbit on Janus having two faces because I think this applies to Ziggy a lot. He appears to be emotionless, cold, and detached. However, when he allows himself to be, he can be full of emotion. Deep inside, he is a very caring and loving person. However, he had so much ripped from him, so he puts on the other face in order to protect himself from the pain.
Name Characteristics
The name Jan has several characteristics which directly apply to Ziggy. These are from kabalarians.
"The name Jan creates the urge to be creative, independent and original, we point out that it limits self-expression and friendly congeniality with a tendency to be moody."
Although Jan doesn't rub off as an incredibly creative individual, he did try to be independent and original during his life as a human. Although he wanted to follow in the footsteps of his father, he didn't want to end up like him, being killed in the line of duty, abandoning his family. He was also a very independent and solitary person. Jan also did have a tendency to be very moody at times. We see this even more during the three main episodes of the series.
"The name Jan can cause tension or accidents to the head."
I found this bit of information hilarious! Jan committed suicide by shooting himself in the head.
The name of Jan gives you a very individual, reserved, and serious nature. Jan's prefer to be alone with their thoughts rather than in the company of others.
Ziggy always was a very reserved and serious person. Most of the time when we see him, he is usually alone, or sometimes with MOMO. In Pied Piper he seemed to prefer being alone or with his new family. He didn't seem very comfortable at outings with the people he worked with.
The name of Jan restricts spontaneity in association and the fluency of verbal expression. When you are required to express yourself in personal matters requiring finesse and diplomacy, you feel awkward and embarrassed. Although you realize perfectly well what is expected of you, you are unable to find the right words, and hence you end up saying something inappropriate in a candid way. You can express your deeper thoughts and feelings best through writing.
Jan had a very hard time trying to express his feelings and thoughts to those around him. We see this namely around Sharon and Joaquin. Though he never told her in the in-game dialogue that he was in love with her, he finds a way to express it in a very awkward manner. He also has no idea what to tell Joaquin in a lot of situations.
When we meet him in Episode I, much of his dialogue is very abrupt and to the point. He doesn't speak about what he's really thinking, and he's pretty much a mystery to those around him. Nobody really understands his inner motives. It's assumed by most of the party that he's merely following orders, and thinking of numbers and strategy. However, by the second disk of Episode II, he sticks around with the party because he cares a lot for MOMO. Though in the first two games, he never actually comes forward with his feelings. Perhaps it's just a mutual and unspoken understanding? Perhaps Episode III will have a few moments that shine more light on Ziggy's struggles to convey his feelings to those he cares for.
Sauer
The word sauer dates back to the word "suraz", which is the origin of our English word, "sour". It actually means sour, salty, or bitter. The Russian form, "syroi" means moist or raw.
This last name is very fitting for him. From a very early age, Jan was bitter and sour from loosing his father, and then mother. Later on, he finally allowed himself to open up to someone. Only to have them taken from him as well. After committing suicide, he woke up two years later as a cyborg. At this point, he became dangerously bitter, and very rightly so. He wanted to remove every trace of his existence. He forced himself to think of his missions and strategy, just as he did when he was a human, to avoid thinking of the pain. Then, he began replacing parts of his body with mechanical ones, eventually wanting to become a machine. This way, he would never have to feel the emotional pain, or endanger anyone else that he cared for. However, this is changed completely when MOMO comes into the picture.