Shel

a couple = as many as you want it to mean
a few = as many as you want it to mean
several = as many as you want it to mean
many = as many as you want it to mean
lots = as many as you want it to mean
a dozen = as many as you want it to mean¹
a score = as many as you want it to mean
multitudes = as many as you want it to mean
a vast amount = as many as you want it to mean
countless = as many as you want it to mean

1. But consider adding "or so" at the end just in case

one of my favorite things to be jokingly prescriptive about is that "myriad" means "a whole lot", but "a myriad" means "exactly 10,000"

similarly, I like to insist that japanese 八百万やおよろず means exactly 8,000,000

Forty is the largest number. After forty it's not worth counting. That's basically infinity