n. An entrepreneur who creates a series of new companies.
2000
I asked 15 or so well-connected people in the local tech community to talk about what trends, people and companies we should watch in 2001…Trends: There will be more serial entrepreneurs. Despite the carnage, some people can't help but start companies again. And again.
1991 (earliest)
OK, once is not enough. Lots of serial entrepreneurs, who spawn one company after the next, swear it."
The first print use of this phrase that I could find is from a 1991 Inc. magazine article. However, the author's relatively casual use of the phrase (she defines it, but she doesn't put it in quotation marks) suggests that it had been "in the air" for at least a little while before that.