Definition of upas
1 : a tall tropical Asian tree (Antiaris toxicaria) of the mulberry family with a latex that contains poisonous glycosides used as an arrow poison; also : a poisonous concentrate of the juice or latex of a upas
2 : a poisonous or harmful influence or institution
Origin and Etymology of upas
Indonesian Malay pohon upas poison tree
First Known Use: 1814
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