(名詞) 化療 (chemotherapy) 後的記憶力衰退 (健忘) 及心智功能減弱現象。亦寫成 chemo fog, chemo-fog。
這個字最初是以兩個字 chemo fog 的型態出現，然後變成 chemo-fog，最後再變成一個字 chemofog。值得注意的是，在英文中，與 chemofog 同義的用字或用語還有 chemobrain (或 chemo brain) 和 brain fog，它們出現得比較早，而且比 chemofog 常用許多。
Dr Janette Vardy from the Sydney Cancer Centre, told the Clinical Oncological Society of Australia Annual Scientific Meeting 'chemofog' had previously been assumed to be temporary, but for 20 to 30 per cent of patients, it had been shown to be ongoing. "It is only in the last 10 years that we have recognised 'chemofog' or 'chemobrain' as a condition," Dr Vardy said. "For a long time some oncologists didn't believe it was real and it was all in the mind.
—"Chemo may leave brain fog," Science Alert, November 18, 2009