optimum

Where does the word "optimum" come from? It comes from Latin optimus, and was adopted directly into English (1879).

Optimum’s story begins in Latin: optimus meant “best.” Best, the superlative of bonus (good). It reached English by 1879 as optimum. Latin 'best', neuter of 'optimus'; biologists used it for ideal growth conditions. Today, optimum means the most favorable condition or degree for a particular purpose.

1. Stage 1 · Latin · ancient optimus "best", best, the superlative of bonus (good).
2. Stage 2 · English · 1879 optimum "the most favorable condition for growth or success", Latin 'best', neuter of 'optimus'; biologists used it for ideal growth conditions.