Wiktionary
vb. 1 (context intransitive English) To be engaged in business, to be involved in commerce or trade. 2 (context slang English) To urinate.
Usage examples of "do business".
Someone who knows that he can count on you is more likely to do business with you.
Just consider what would happen if a top-tier venture capital firm required the companies in which it invested to place 1 percent of their equity into a public charity serving the communities in which they do business.
Even so, what we regard as a tolerable level of internal corruption is -- thanks to our rules on financial transparency -- positively microscopic compared to that in just about every other organisation we do business with, and it is a matter of considerable pride for us that in any given transaction or deal we will almost without exception be the most honest and principled party involved.