focus

Where does the word "focus" come from? It comes from Latin focus, and was adopted directly into English (1640s).

Focus’s story begins in Latin: focus meant “a hearth, a fireplace.” Literally a hearth, fireplace, the center of a household. It reached English by 1640s as focus. Latin 'hearth'; Kepler used it in 1604 for the burning point of a lens. Today, focus means the center of interest or activity, or the point where light rays converge.

1. Stage 1 · Latin · ancient focus "a hearth, a fireplace", literally a hearth, fireplace, the center of a household.
2. Stage 2 · English · 1640s focus "the point where light or attention converges", Latin 'hearth'; Kepler used it in 1604 for the burning point of a lens.