written/formal; in speech use 하지만 or 그런데
but, however
Example
그 식당은 비쌉니다. 그러나 음식이 맛있습니다.
That restaurant is expensive. However, the food is delicious.
Word parts
From 그러하다 (to be so) + -나 (but). More written than 하지만 or 그런데.
Good to know
Mostly used in writing and formal speeches.