Meaning:
“偶像” means “idols,” “失” means “to lose,” and “格” means “required format.” This term, which has existed in the Chinese language for a long time, is similar to another term “出格” (to breach boundaries). In Japanese, the term means “losing one’s qualifications,” with the best known example being the title of a novel by Osamu Dazai called “No Longer Human.” This term, often used by fans, refers to the scenario where an idol has acted against their professional ethics, such as dating a showbiz outsider or lip syncing during a live concert.
Example:
A: 为什么粉丝要求金钟大退队？
Wèishénme fěnsī yāoqiú jīnzhōngdà tuìduì？
Why do fans ask Korean idol Chen to exit EXO?
B: 他们的理由是偶像失格。他忽然公布婚讯，而且新娘已经怀孕数月。
Tāmen de lǐyóu shì ǒuxiàng shīgé。Tā hūrán gōngbù hūnxùn，érqiě xīnniáng yǐjīng huáiyùn shùyuè。
They think he has breached boundaries. He suddenly announced his marriage, and the bride is months into pregnancy.