Histone acetylation, including acetylated H3K14 (H3K14ac), is generally linked to gene activation. Monomethylated histone H3 lysine 4 (H3K4me1), together with other gene-activating marks, denotes active genes. In contrast to usual gene-activating functions of H3K14ac and H3K4me1, we here show that the dual histone modification mark H3K4me1-H3K14ac is recognized by ZMYND8 (also called RACK7) and can function to counteract gene expression. We identified ZMYND8 as a transcriptional corepressor of the H3K4 demethylase JARID1D. ZMYND8 antagonized the expression of metastasis-linked genes, and its knockdown increased the cellular invasiveness in vitro and in vivo. The plant homeodomain (PHD) and Bromodomain cassette in ZMYND8 mediated the combinatorial recognition of H3K4me1-H3K14ac and H3K4me0-H3K14ac by ZMYND8. These findings uncover an unexpected role for the signature H3K4me1-H3K14ac in attenuating gene expression and reveal a metastasis-suppressive epigenetic mechanism in which ZMYND8's PHD-Bromo cassette couples H3K4me1-H3K14ac with downregulation of metastasis-linked genes.