False friends are words in two languages that look or sound similar but have different meanings. In the example you provided, "spermophobia" is a false friend because it looks like it should mean "fear of sperm," but actually means "fear of germs."
False cognates are a type of false friend where the words are derived from the same root but have diverged in meaning over time. For example, the English word "bank" and the Spanish word "banco" both come from the Latin word "bancus," but they have different meanings.
So, "spermophobia" is a false friend because it tricks you into thinking it means something different than it actually does.