The word "Nephthalim" can be a bit tricky to spell, but it's pronounced neff-thuh-lim. In IPA phonetic transcription, that's /ˈnɛfθəlɪm/. The first syllable is pronounced with a short "e" sound, followed by the "f" sound and the "th" sound, which is made by putting your tongue between your teeth. The second syllable is pronounced with a short "i" sound and the "-im" ending is pronounced like "im" (rhymes with "him"). Overall, "Nephthalim" is spelled just like it sounds!
The word "Nephthalim" is derived from the biblical Hebrew term "Nephilim". In the Book of Genesis in the Bible, specifically Genesis 6:4, the Nephilim are described as the offspring of the "sons of God" and the "daughters of men". These Nephilim are often understood to be a group of giants or superhuman beings. The Hebrew word "Nephilim" is thought to come from the root "naphal", which means "to fall" or "to cause to fall". The exact origins and meaning of the Nephilim are subject to various interpretations and debates among biblical scholars.