Complex sentence: In the world where Lyra Belacqua comes from, they are roughly analogous to gypsies--the name "gyptian," like "gypsy," is obviously derived from "Egyptian"--the original English name for the Roma.
Split into simpler sentences: In the world where Lyra Belacqua comes from, they are roughly analogous to gypsies. The name "gyptian", like "gypsy", is derived from "Egyptian", the original English name for the Roma.