Darwinian is an adjective that means marked by competition.

Our word of the day comes from 19th century scientist Charles Darwin. His theory of evolution by natural selection portrays the natural world as a fiercely competitive environment. To refer to something as Darwinian means you are suggesting a great deal of cutthroat competition.

I liked working at the office, but things could get Darwinian from time to time. I could sense that if you couldn’t keep pace with everyone else, you were gone.