noun, na-adjective, noun which may take the genitive case particle 'no'
prone to illness; sickly; often ill
Describes a person who tends to get sick frequently or has a weak constitution. Often used with ～の人 or as a な-adjective.
彼は子供の頃から病気がちで、よく学校を休んでいた。
He has been prone to illness since childhood and often missed school.
病気がちな人は、普段から栄養に気をつけたほうがいい。
People who are often ill should pay attention to their nutrition on a daily basis.
Compound of 病気 (illness) and the suffix がち, which indicates a tendency or proneness. The kanji spelling 勝ち is ateji and not etymologically related to the meaning.