This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
癄 combines 疒 (sickness) with 焦 (scorch, char, fret). The exact historical development is uncertain, but it likely relates to a wasting or emaciating condition, consistent with the kun readings やつれる and やせる.
The sickness enclosure 疒 wraps around 焦, suggesting a condition that scorches or wastes the body, like emaciation.
For ショウ, imagine a person wasting away from sickness, and their only comfort is a show on TV: show -> ショウ, while the body grows thin inside the sickness enclosure.