The definition of although is regardless of a fact.(conjunction)
Buying something even if it is expensive is an example of although.
See although in Webster's New World College Dictionary
Origin: ME < all, al, even + though
See although in American Heritage Dictionary 4
Origin: Middle English
Origin: : al, all; see all
Origin: + though, though; see though. Usage Note: As conjunctions, although and though are generally interchangeable: Although (or though) she smiled, she was angry. Although is usually placed at the beginning of its clause (as in the preceding example), whereas though may occur elsewhere and is the more common term when used to link words or phrases, as in wiser though poorer. In certain constructions, only though is acceptable: Fond though (not although) I am of sports, I'd rather not sit through another basketball game.
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