Definitions

1. noun

A hypothetical subatomic particle that is predicted by some theories of particle physics, particularly by some versions of the Standard Model. It is a very light particle and is thought to be a potential candidate for dark matter.

“The discovery of the axion could be a major breakthrough in the field of particle physics.”

2. noun

A small, unassuming person or thing.

“He’s a bit of an axion in our company, but his work is always exceptional.”