The conjunction albeit has been labeled archaic, but it appears to be making a comeback, especially in American English. It means though or although, but it is not interchangeable with these words in all circumstances. Think of it as a shorter way of saying although it is or although it be.
Examples
Albeit is often used to introduce an adjectival or adverbial phrase that makes a concession about the preceding noun or verb—for example:
This morning we gratefully received a long overdue pardon, albeit temporary, from the gray drearies which have toyed with our sanity all winter. [Cape Cod Chronicle]
The right-hander’s ability to dominate hitters returned, albeit sporadically, as he provided glimpses of the skill that won him the last two National League Cy Young Awards. [MLB.com]
The sponge was very absorbent, soaking up all the soda, albeit with some effort. [New York Times]
In rarer cases, albeit may introduce a dependent clause—for example:
The good news is that he is back at Tannadice and has resumed his duties, albeit he will not rejoin the board. [BBC]
Here, although would work just as well.