Wolf's-milk \Wolf's"-milk`\, n. (Bot.) Any kind of spurge (Euphorbia); -- so called from its acrid milky juice.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Euphorbia \Eu*phor"bi*a\, n. [NL., fr. L. euphorbea. See Euphorrium.]

(Bot.) Spurge, or bastard spurge, a genus of plants of many species, mostly shrubby, herbaceous succulents, affording an acrid, milky juice. Some of them are armed with thorns. Most of them yield powerful emetic and cathartic products.

Source: Webster's Revised Unabridged Dictionary (1913)