idiopathic /id-i-ō-pathˈik/

1. (of a state or experience) peculiar to the individual
2. (of a disease, etc) arising spontaneously from some unknown cause, primary

• night-blooming cereuses
• night-brawler
• night-brawlers
• nightcap
• nightcaps
• night-cart
• night-carts
• night-cellar
• night-cellars
• night-chair
• prep school
• prep schools
• prepubertal
• prepuberties
• prepuberty
• prepubescent
• prepuce
• prepuces
• prepunctual
• preputial
• prequalification
• pre-qualified
• pre-qualifies
• pre-qualify
• pre-qualifying