I heard the phrase from many mathematician using in the colloquials.

It seems to be magical term. I found algebraic geometer using it. I was never bother about it until one of my professor responded to one my question as follows:

The graph product is by definition the fundamental group of the space K obtained from the underlying graph by blowing up.

I googled it, but nothing relevant came up.

I heard the phrase from many mathematician using in the colloquials. I heard algebraic geometer using it. I was never bother about it until one of my professor responded to one my question as follows:

The graph product is by definition the fundamental group of the space K obtained from the underlying graph by blowing up.

what this phrase means in that context.