citrovorum factor
noun
ci·trov·o·rum factor sə-ˈträ-və-rəm- 
: a metabolically active form of folic acid that has been used in cancer therapy to protect normal cells against methotrexate
Word History
Etymology
New Latin citrovorum, specific epithet of Leuconostoc citrovorum, bacterium that requires this form of folic acid
First Known Use
1948, in the meaning defined above
Medical Definition
citrovorum factor
noun
ci·trov·o·rum factor sə-ˈträv-ə-rəm-
: leucovorin