expression, noun
feigning illness; pretending to be sick
Almost always used in the pattern 病気のふりをする. Describes the act of pretending to be ill, often to avoid something.
See also: 振り (ふり)
彼は学校に行きたくなくて、病気のふりをした。
He didn't want to go to school, so he pretended to be sick.
会議に出たくないから、病気のふりをしようかな。
I don't want to attend the meeting, so maybe I'll pretend to be ill.
仮病 is a more formal or direct noun meaning 'feigned illness', while 病気のふり is a common, slightly softer expression used in everyday speech.
Compound of 病気 (illness) + の (possessive particle) + ふり (pretending). The ふり part comes from 振り, meaning 'pretending' or 'feigning'.