Willingness to take risks, as in His sporting blood won't let him stay away from the races. This idiom uses sporting in the sense of “associated with gambling.”
Content related to sporting blood
Words nearby sporting blood
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.