出典:Wiktionary
From Middle English *overthenken, *overthenchen (compare Middle English overthinken (“to grieve; have regrets; be sorry; be anxious”)), from 古期英語 oferþenċan (“to think over; consider”), equivalent to over- + think.
overthink (三人称単数 現在形 overthinks, 現在分詞 overthinking, 過去形および過去分詞形 overthought)