(ˌ)mərˌkyu̇rēˈalə̇s, -āl-, -äl- noun
Etymology: New Latin, from Latin ( herba ) mercurialis dog's mercury
1. capitalized : a small genus of slender herbs (family Euphorbiaceae) having opposite pinnately-veined leaves and apetalous flowers in interrupted axillary spikes — see boys-and-girls 2, dog's mercury
2. -es : an herb ( Mercurialis annua ) formerly dried for use as a purgative, diuretic, and antisyphilitic