ague tree
/ˈeɪɡjuː ˌtriː/Now historical
noun
The sassafras, Sassafras albidum, parts of which (especially the root and bark) were formerly used in the treatment of fevers.
Origin
Late 16th century; earliest use found in John Gerard (c1545–1612), herbalist. From ague + tree, with allusion to the use of the root of this tree in the treatment of fevers.