The phrase "several billions" means a large number, more than a few billion. It refers to a count of billions but does not specify the exact number. Full definition
The costs of wrapping the space - shuttle program leave the agency with a projected shortfall of several billion dollars over the next few years. (discovermagazine.com)
Corn futures are among the most widely traded agricultural contracts, with an average daily volume of several billion dollars. (commodityhq.com)
Too big and the star will burn out in a few million years, compared to our more energy - efficient sun which is slated to last for several billion years. (bigthink.com)