an·ti·me·tab·o·lite 
(ăn′tē-mĭ-tăbə-līt′, ăn′tī-)
(ăn′tē-mĭ-tăbə-līt′, ăn′tī-)n.
A substance that closely resembles an essential metabolite and therefore inhibits physiological reactions involving that metabolite.
an′ti·met′a·bolic (-mĕt′ə-bŏlĭk) adj.