Although

King James Dictionary

Altho'Ugh, altho', obs. verb, or used only in the Imperative. Grant all this be it so allow all suppose that admit all that as, "although the fig tree shall not blossom."  Habakkuk 3 . That is, grant, admit or suppose what follows - "the fig tree shall not blossom." It is a transitive verb, and admits after it the definitive that - although that the fig tree shall not blossom but this use of the verb, has been long obsolete. The word may be defined by notwithstanding, non obstante as not opposing may be equivalent to admitting or supposing.

Webster's Dictionary

(conj.) Grant all this; be it that; supposing that; notwithstanding; though.