On the old blog, I wrote several posts on the definition of 'Marketing', and I have the same interest in finding a good definition for the world 'Brand'. An article called 'F*ck. Love. Brand.' over at UX Mag (User Experience) take a look at the sacred and the profane aspects of this question:

Catholics believe that there is no difference between God The Father, God The Son, and God The Holy Spirit, to them there’s just God. God is all three, and all three are God, they call this the Holy Trinity.

Similarly in business we have, The (company name) Brand, The (company name) Culture, and the The (company name’s) Customer Experience. Yet all of these simply make up The Company. Like the religious reference above, they’re one and the same.

The word brand is a generic term that I believe should never be used in a non-generic sense. I don’t want people discussing the Missing Link brand (culture, or customer experience) for me, they should only ever be discussing Missing Link. Internally and externally, there is and should be no differentiation.

He goes even farther in his conclusion, arguing in effect that the company and everything it does is the brand. That may be more true than some narrow definitions, but seems like a cop out to me. For now I'm sticking with the idea that a brand is a reputation, the sum (or prevailing mass) of what people think about a company (or a person). From there it's relatively easy to understand how different business actions or decisions will impact a brand, or not impact it.

I don't think that's the ultimate definition though. Any more ideas would be appreciated.