Source : Webster's Revised Unabridged Dictionary (1913)

Houseleek \House"leek`\, n. [House + leek.] (Bot.)
   A succulent plant of the genus {Sempervivum} ({S. tectorum}),
   originally a native of subalpine Europe, but now found very
   generally on old walls and roofs. It is very tenacious of
   life under drought and heat; -- called also {ayegreen}.