Hereditary means passed down from parent to child. A hereditary condition, hereditary title, hereditary peer.
In medicine it means carried in the genes and inherited, which is narrower than genetic — a genetic condition can arise new in one person, and a hereditary one came from a parent. In politics, a hereditary title passes by birth, and the hereditary peers in the House of Lords were reduced to ninety-two in 1999. Note heredity, heir; and that hereditary and inherited are near-synonyms.
1adjectivehereditaryPassed down from parent to child.
“The eye disease is hereditary, so her children were tested too.”
2adjectivebirthPassing by birth, of a title.
“Roughly ninety-two hereditary peers remain.”
hereditary is a quality of being inherited.
Latin hereditarius comes from heres, an heir. Heir, heritage and inherit come from the same inheritance, and the h in heir has never been pronounced in English.
Proto-Indo-European
*ǵʰeh₁-
Latin
hērēditārius
Middle English
hereditarie
English, today
hereditary
Built from
Middle English hereditarie, from Latin hērēditārius, from hērēditās (“inheritance”), from hērēs (“heir”).
Etymology from Wiktionary, CC BY-SA