As a student of Spanish, it's always weird to me to see the word molestar, which means "to annoy". My English-oriented brain always jumps to the word molest, which obviously is much worse. As you may expect, the two words are related, in this case through the Latin word molestare, which also had a meaning of "annoy". The connection to the modern word may be found in Old French molester, which meant something more like "torment" or "harass" and eventually shifted in meaning to give us the sexual abuse definition. The adjectival form of molestare, molestus, meant something like "burdensome" and links us to the noun form, moles, meaning "mass" or "boulder" (the idea being that a large rock was burdensome to travelling). That, finally, derives from Proto-Indo-European meh, "to exert".
Adam Aleksic, a freshman studying linguistics at Harvard University, has been described as the internet's sixth most famous etymologist. He has disturbing interests in words, vexillology, geography, board games, limericks, and law, and he loves writing about himself in the third person.
The Etymology Nerd