To grow up together, to increase alongside something else. In Matthew 13:30, Jesus's parable instructs servants to 'let both grow together until the harvest'—wheat and weeds are to coexist until the final separation. The word emphasizes simultaneous, parallel growth: both are increasing in the same field at the same time. Jesus interprets this as the church age, when righteous and wicked grow together in the world until judgment. Premature separation would damage the wheat; only at harvest can perfect distinction be made. The command to let them grow together counsels patience with imperfect church purity.