focus-, foci-

(Latin: hearth, fireplace; fire, flame; central point, center)

The word "focus" was introduced into mathematics by Johannes Kepler in 1604 with the meaning of any "central point".

Cross references of word groups that are related, directly, indirectly, or partly to: "fire, burn, glow, or ashes": ars-, ard-; -bust; cand-, cend-; caust-, caut-; crema-; ciner-; ether-; flagr-; flam-; fulg-; gehenna-; ign-; phleg-; phlog-; pyreto-, -pyrexia; pyr-; spod- (ashes; waste); volcan-.