feigned illness; pretended sickness
Refers to an illness that is faked or exaggerated, often to avoid work or obligations.
彼は作り病で学校を休んだ。
He skipped school by feigning illness.
作り病を使うのはよくない。
It's not good to use a feigned illness.
Compound of 作り (tsukuri, 'making' or 'fabrication') and 病 (yamai, 'illness'). The exact historical derivation is uncertain, but the meaning is transparently 'fabricated illness'.