locoweed
noun
lo·co·weed ˈlō-(ˌ)kō-ˌwēd 
: any of several leguminous plants (genera Astragalus and Oxytropis) of western North America that cause locoism especially in livestock
Example Sentences
Recent Examples on the Web The unincorporated community got its name after the locoweed, a common North American poisonous plant synonymous for causing livestock to grow weak and lose muscular control. 
Timothy Fanning, San Antonio Express-News, 28 Jan. 2022 The drug is usually produced from wild hemp or locoweed which can be found on vacant lots and along railroad tracks in every state. Eric Limer, Popular Mechanics, 20 Apr. 2018
Timothy Fanning, San Antonio Express-News, 28 Jan. 2022 The drug is usually produced from wild hemp or locoweed which can be found on vacant lots and along railroad tracks in every state. Eric Limer, Popular Mechanics, 20 Apr. 2018 Word History
First Known Use
1879, in the meaning defined above
Medical Definition
locoweed
noun
lo·co·weed ˈlō-(ˌ)kō-ˌwēd
: any of several leguminous plants (genera Astragalus and Oxytropis) of western North America that cause locoism in livestock