although

Etymology

From Middle English althagh, from Old English compound of eall (“all (emphatic)”) + þēah (“though”).

conj

1. Though, even though, in spite of or despite the fact that: introducing a clause that expresses a concession.
   Although it was very muddy, the football game went on.
   The patients, (al)though getting stronger, will not come off their medications.
   With the north London derby to come at the weekend, Spurs boss Harry Redknapp opted to rest many of his key players, although he brought back Aaron Lennon after a month out through injury. September 29, 2011, Jon Smith, “Tottenham 3-1 Shamrock Rovers”, in BBC Sport
   Although there are dozens of different types of gems, among the best known and most important are diamond, ruby and sapphire, emerald and other gem forms of the mineral beryl, chrysoberyl, tanzanite, tsavorite, topaz and jade. 2012-03, Lee A. Groat, “Gemstones”, in American Scientist, volume 100, number 2, archived from the original on 2012-06-14, page 128
2. But, except.
   It was difficult, although not as difficult as we had expected.