This verb means to invoke a curse upon someone, calling down divine judgment or binding oneself by oath. Matthew 26:74 describes Peter beginning 'to curse' as he denies knowing Jesus—either cursing himself if lying or cursing Jesus to prove his dissociation. The infinitive follows 'began,' indicating the start of increasingly desperate oath-taking. This variant form relates to the noun for 'curse' (G2652). The multilingual witnesses show 'curse/maldecir/maudire,' emphasizing the verbal act of pronouncement. Peter's cursing marks the nadir of his denial, just before the rooster crows.