sacred fire; sacred flame
General term for a holy or ceremonial fire, often in religious or traditional contexts.
A sacred fire is kept burning continuously at the temple.
Olympic flame; Olympic torch
Specifically the flame of the Olympic Games; often used in phrases like 聖火リレー (torch relay).
See also: オリンピック聖火
The Olympic torch relay passed through the city.
The sacred flame was lit at the opening ceremony.
The athlete held the torch high and entered the stadium.
The sacred flame went out due to strong wind.
The runners carried the flame from town to town.
聖歌 (a hymn or sacred song) is pronounced identically to 聖火 (a sacred/Olympic flame) but refers to music, not fire.
生花 (fresh-cut or arranged flowers) shares the せいか reading with 聖火 but has nothing to do with fire.
精華 (the essence or quintessence of something) is a homophone of 聖火 but is an abstract noun with no connection to flame.
Compound of 聖 (holy, sacred) and 火 (fire). The Olympic sense is a modern extension.