The word nice is an etymological hot mess, so bear with me for several moments. When it entered English in the 1300s, it meant "foolish". Yes, that's right. It gets better: later it meant "timid", "fussy", "delicate", "careful", "doubtful", and "strict". Basically, throughout its history, nice assumed the role of sort of a jack-of-all-trades word. It was very difficult to tell what people meant much of the time, and many writers like Shakespeare and Austen played with their words based on this premise. The modern definition started to emerge in the eighteenth century, but it was still confusing. Eventually, highborn people gentrified the word; they wanted the prettiest meaning to prevail. That's what happened, and why it means "pleasant" today. Going back to the beginning, nice ("foolish") came from Old French nisce, or "ignorant", from Latin nescius, also "ignorant", from the verb form nescire. Now, nescire is a compound of ne-, a prefix meaning "not", and scire, a root meaning "to know". Scio, through Proto-Italic skijo, is from the Proto-Indo-European reconstruction skios, a word for "dissect", sonething that's done in intellectual thought and is therefore connected to knowledge. So many definitions; it's kind of nice that no one need know what you mean!
Adam Aleksic has been described as the internet's sixth most famous etymologist. He loves writing about himself in the third person, he's a freshman at Harvard University, and he has disturbing interests in linguistics, vexillology, geography, board games, limericks, and law.
The Etymology Nerd