Infinitesimal is an adjective that means immeasurably small. It is also a noun that refers to a very small amount.

The root word of infinitesimal is ‘infinite,’ which means ‘not finite,’ or ‘not having limits.’ ‘Finite’ comes from the Latin word ‘finitus,’ (FEE knee toos) meaning ‘finished.’ When something is called infinitesimal, it is infinitely small or so small it cannot be measured.

I played on a championship softball team for two years, but I get the feeling my contribution to the team was infinitesimal. Without me, they may have scored a few less runs, but that’s about it.