hooked comes from hook + -ed; hook descends from Old English hōc ('hook, angle'), from Proto-Germanic *hōkaz. Morphologically, the ending is part of the etymology: the suffix is attached to the older base named in the history, producing a later English derivative. In present English, the adjective sense is "curved like a hook, or addicted to or captivated by something", so the historical development ends in a clearly identifiable modern dictionary use. The same base also appears in related forms such as hook and unhook. Its semantic neighborhood includes curved, bent, aquiline, and addicted, which helps locate the modern sense without adding a separate etymological claim. The named historical forms include Old English hōc and Proto-Germanic *hōkaz.