ルーザーMeanings1nounloserA person who fails or is unsuccessful, often used in a derogatory or self-deprecating way. Common in casual speech and online contexts.あいつは本ほん当とうにルーザーだな。That guy is a real loser.試し験けんに落おちて、自じ分ぶんがルーザーに思おもえた。After failing the exam, I felt like a loser.