An entrepreneur was someone who started a business, rather than taking over or investing in a pre-existing one.
In 1996, Braxton summed up Henry Starling as supposedly being a "philanthropist, entrepreneur, outstanding citizen" (at least to those who weren't aware he owed his success to the theft of Braxton's timeship). (VOY: "Future's End")
According to Quark, "the true entrepreneur knows how to sniff the wind." He was referring to being able to forecast trends, such as the increasing Human presence on Deep Space 9, and adjust one's business strategies accordingly. (DS9: "If Wishes Were Horses")
Odo sarcastically referred to the Ferengi practice of preserving their remains via vacuum dessication as "a fitting and distinguished way to honor the memory of great Ferengi entrepreneurs". (DS9: "The Alternate")