Her prediction wasn't just speculation; it was an educated guess based on years of research.

an 是不定冠词，用于表示"一个"或"一种"。 educated 是形容词，来自动词 educate（教育），这里引申为"经过训练的"或"有依据的"。 guess 是名词，意思是"猜测"或"推测"。 educated guess 指基于专业知识和经验做出的合理推测，即"有根据的猜测"。