plēroō

The plainest sense is to fill an empty space until it is full: a house fills with fragrance or sound, a net fills with fish, a low place is filled in and leveled. From there the word moves to people. A person can be filled the way a container is, but with something that takes hold of the inner life: joy, sorrow, comfort, the Spirit, knowledge, or even wickedness. The picture is the same in both: something pours in until there is no room left for anything else.

Because the image is one of being completely filled, the word often carries the idea of full measure, not just a partial topping up. To be filled with joy is to have joy brimming over, not merely present. This is why English translations reach for "full" as much as "fill": the point is that the supply is total.

When the New Testament speaks of God filling all things, or of believers being filled with all the fullness of God, this same picture is stretched to its largest scale: God's presence saturating everything, leaving nothing untouched.

When the thing being filled is not a space but a span, the word means to bring that span to completion. A period of time runs out and is full: a set of forty years, a stretch of days, an appointed season. The same is true of a fixed number: a count is filled up when the last of them is reached.

Applied to work, the word means to carry a task all the way through rather than leaving it half done. A ministry, a course of service, or a commission is filled when it has been completed in full. This is the sense behind finishing a journey of service, accomplishing a work, or rounding out a stretch of preaching so that nothing is left undone.

The shading is close to the plain idea of filling: a measure that was partly used is now used up entirely. What is added here is the dimension of time or quantity rather than physical space.

This is the weightiest use of the word in the New Testament. Something has been said or required, and the word means to make it fully come true. A prophecy is fulfilled when the event it pointed to actually happens; a promise is fulfilled when it is kept; the time is fulfilled when the long-awaited moment finally arrives.

The Gospels return to this again and again with the phrase "that it might be fulfilled which was spoken." The claim is not merely that an old text happens to fit a new event, but that the earlier word was always headed toward this and has now reached it. The same idea covers Jesus saying a scripture is fulfilled in the hearing of his audience: the text has come to life in front of them.

A closely related shading concerns the law. To fulfill the law is not to add to it but to bring it to its full intent, so that what it was always aiming at is satisfied. Loving one's neighbor fulfills the law because it does the whole of what the law was for. Reading later ideas of mere rule-keeping back into this can flatten it; the word points to bringing something to its complete and intended realization, not just ticking a box.