She often fantasizes about becoming an astronaut, even though she's afraid of heights.

fantasizes 是动词 fantasize 的第三人称单数形式。fantasize 由名词 fantasy（幻想）加上动词后缀 -ize 构成，意思是"幻想、想象"。fantasizes 表示"经常性地进行幻想"的动作。