Means “Caesar is not.” This is what the early Christians understood and adopted as their politically subversive catch phrase, turning the common phrase “Caesar is Lord” upside down.
This is what the mob who pushed for Jesus’ crucifixion were counting on as their argument for conviction: “Anyone who claims to be a king opposes Caesar.” And in the end, they were right. It was Jesus’ claim to kingship that got him killed.
Is this what we mean when we say “Jesus is Lord” today? Even a cursory glance within my own heart reveals at least a handful of other “lords” that I honor.