hys·tri·coi·dea \ˌ ̷ ̷ ̷ ̷ˈkȯidēə\noun plural Usage: capitalized Etymology: New Latin, from Hystric-, Hystrix + -oidea 1.in some classifications: a major division of hystricomorph rodents equivalent to the Hystricidea 2.in some classifications: hystricomorpha