～狂
～きょう · ～kyou · JLPT N1 · noun
lunatic
狂 = 犬 (dog) + 王: originally a wild, mad dog. So 野球狂 = a baseball maniac, mad about baseball
Attach it to a noun for an obsessive fan: 読書狂 is a bookworm, 映画狂 a movie buff. The same kanji means crazy or mad, so read it as 'mad about X'.
狂 — dog radical 犭+ king 王
Originally written with 犬 (dog) as the semantic component and 㞷 as the phonetic, depicting a wildly running dog. The meaning extended from 'mad dog' to 'crazy, wild, unrestrained' in general. The modern form simplifies the right side to 王.