houseleek

noun

house·​leek ˈhau̇s-ˌlēk 

: a pink-flowered thick-leaved European plant (Sempervivum tectorum) of the orpine family that tends to form clusters of rosettes and is often grown in rock gardens

broadly : sempervivum

Word History

Etymology

Middle English houslek, from hous house entry 1 + lek leek

Note: The formation is paralleled by Middle Dutch huuslooc, Middle High German huslouh, Old Danish husløk, and Old Swedish husslök. The name is alleged to have originated from the custom of growing Sempervivum tectorum (the specific epithet meaning "of the roofs") on the roofs of houses to ward off lightning.

First Known Use

14th century, in the meaning defined above