Wa `aleikumus-Salaam. What makes you ask that? Who said it might be? It is not among any of the (more than 99) Names I know, but though it is not for us to say it is not His Name (because of a du`aa of the Prophet -sAaws- for troubles/worries in Hisnul-Muslim, which shows that Allaah has Names that even only He knows about. It was related by An-Nasaaii among others, and is authentic) then does it have a meaning? Every Name of Allaah has a meaning, and relates to an Attribute in the manner befitting Him -SubHaanahu wa ta`aalaa. It doesn`t sound like it, and why would`t you tell us how it should be written in arabic, because in a way `sahaabir` it`s not a Name of Allaah in arabic, like `Allaah` too is not His Name. To pronounce it you have to know how to pronounce pure arabic, and how it`s spelled. And you are asking a great question, because the knowledge of Allaah is the Highest of all sciences, and has to be learned and studied properly. I will provide for you some links to study some more.
Now first I`m checking my dictionary if I find any word similar to what it might relate to in arabic...
`Soobir` without with `Saad`, not `siin`, and without `ha`, or `Ha` is of course an attribute as we know, and it means someone, who has `Sobr` = patience/forbearance. This might be attributed to Allaah, but I`m not saying it is, because He is `Al-Haliim`, which means more or less the same as a human attribute, and far removed is He from likeness with creation ("Haliim" = He is kind, and does not punish immediately, though He is insulted and disobeyed, but He sends warning and gives opportunities to repent and get forgiveness). And that`s recuires Sobr from a man, and the prophets -as- possessed this quality (and Allaah forgave Junus -as- and even his people after the punishment was already ordered because Junus -as- was too quick to judge them, and he and them too, repented). "Wa Allaahu Qhafuurun Haliim" is mentioned referring to Him -`ajja wa dzall- in Suurat Al-Baqarah, Verse 225, and "Wa `lamuu anna Allaaha Qhafuurun Haliim" in the same Suurat: 235, and in many other places in His Kitaab. But actually the word Sobr is not found in The Kitaab attributed to Him, but only to men. It may be in Sunnah, I`m not sure. If it`s in the Hadiith of At-Tirmithi, where the list of 99 Names is mentioned, you should know that the beginning of the Hadiith is authentic -found also in Al-Bukharis SoHiiH- but the list is not considered by muHaddithuun as a saying of Rasuul -sAaws- and thus the Hadiith as itself is Da`iif (a weak narration). Rather, the 99 Names mentioned in it are probable to have been the respectable Imaams own ijtihaad (striving to find the 99 Names). I`ve studied them among many others, students of knowledge, and scholars, and personally I don`t like the list, and it doesn`t convince me, because some of the Names themselves are not found in The Book or the SoHiiH Sunnah, though they may be attributes, or they relate to actions of Allaah.
Ok, back to the question...
Are you still with me?
No, I`m sorry. There`s no word like that in my digital dictionary of arabic, which has all Quran and SoHiiH Al-Bukhaarii. I tried all combinations with the dictionary, The SoHiiH, and The Quràn, though I knew it`s certainly not I The Quràn. I`ll check `Soobir` from Al-Bukhaarii just in case... No, brother, it`s not there either it just mentiones aHaadiith about making Sobr for the sake of Allaah, and the word nearest to it was `Soobiraa`, or `Soobiran` depending on how you whish to pronounce - so that`s just about a human being, OK.
So there is absolutely no reason to believe anything else except that most likely it is not a Name of Allaah, The Most High. And Allaah knows best.
Here are some links to know about His Names, and how to understand them, and the true Eemaan in Him as taught by His Slave and Messenger MuHammad -Solla Allaahu `aleihi wa `alaa aalihi wa SoHbihi wa sallama tasliiman kathiiraa:

(Some of them maybe difficult to understand first, so I put them in an order, so you can start with the easiest, and so on moving from up to down, and take your time, and don`t listen to many people saying this and that without knowledge, or trying to twist the true meanings. Be patient. Have `Sobr`. And please forgive me they are so many, but they are such jewels of Islam wAllaahi that I hope you can go to them, download them, save them value them, study them, and master them till you are an `aalim of Laa ilaaha ill-Allaah even if it takes you years. Then you can call people to Allaah with knowledge and certainty on the Straight Path of Rasuulullaah -sAaws- by the permission of Allaah. And on The Last Day you will be with the ones you loved, so love Allaah and Rasuul -sAaws)

http://www.salafitapes.com/index.php?option=com_content&task=view&id=636&Itemid=71

http://islamic-knowledge.com/Books_Articles/Quran__Tafseer_Ayat_Al_Kursi__Explanation__Sh_Ibn_ Al_Uthaymeen.pdf

http://islamic-knowledge.com/Books_Articles/Tawheed_First__Sh_Al_Albanee.pdf

http://islamic-knowledge.com/Books_Articles/Three_Fundamental_Principles__Sh_Muhammad_at_Tamim i.pdf

http://islamic-knowledge.com
/Books_Articles/Sunnah__Its_Foundation__Imaam_Ibn_Hanbal.pdf

http://abdurrahman.org/tawheed/removalofdoubts1to11.pdf

http://abdurrahman.org/aqeeda/hamawiyyah.html

Don`t get me wrong, `Allaah` as it is spelled in arabic IS certainly His Name.