What does 'subha-n-allah' mean? I've often heard this being used within the Bangladeshi community, but it just occured to me that I don't know what it means. Where does it come from, and how is it written in arabic.
Subhan'Allāh (Arabic سبحان الله) is an Arabic phrase often translated as "Glorious is Allah." You use it to express both your astonishment and gratitude in a situation where you think that the happening, or bounty, or unique situation can arise only out of the Glory of Allah Subhanatawala.
It is also a great and rewarding act to read this whenever you get an opportunity or after fard prayer (33 times).
Please take a look at http://en.wikipedia.org/wiki/Subhan'Allah for further details. Or see http://islam.about.com/od/glossary/g/subhanallah.htm for a shorter version.
(Happy to answer you question, but you could get the answer by a simple Google search.)