Wiktionary
onychorrhexis
n. (context pathology English) fingernail and toenail brittleness and breakage, such as may be due to excessive strong soap and water exposure, nail polish remover, hypothyroidism, anemia, anorexia nervosa or bulimia, or after oral retinoid therapy.
Wikipedia
Onychorrhexis
Onychorrhexis, (from the words in Greek: onycho-, nail, rhexis-, bursting) also known as Brittle nails, is a brittleness with breakage of finger or toenails that may result from excessive strong soap and water exposure, nail polish remover, hypothyroidism, anemia, anorexia nervosa or bulimia, or after oral retinoid therapy. Onychorrhexis affects up to 20% of the population.