“四射”意思是向四面八方发出去，常常用来形容光、热或者活力。

"四射" means to radiate in all directions, often used to describe light, heat, or vitality.

这个词一般不单独用，比如“光芒四射”和“活力四射”。

This word is generally not used alone, for example in "光芒四射" (radiant light) and "活力四射" (full of vitality).