to dwell, take up residence (pictured as pitching a tent)
The plain sense of this verb is simply to live somewhere, to settle in and stay. It is built from the word for a tent (σκηνή), so its root picture is of pitching camp and taking up residence, but by the first century ordinary Greek had worn that tent image down to the everyday meaning of dwelling in a place. Greek writers used it of soldiers quartering in villages and of a person living wherever they happened to live, with no special weight on the lodging being temporary.
What gives the word its power in the New Testament is not the camping picture but a memory built into Greek-speaking Jewish ears. The Greek Old Testament had used the matching noun (σκηνή) for the wilderness tent where God met Israel, for the tent of meeting, and for the booths of the Feast of Tabernacles, so the whole word family carried the idea of God coming down to live among his people. Every New Testament use of this verb belongs to John, who reaches for it deliberately to say that God has come to dwell with people again.
Because the word itself only ever means to dwell, this is one word with one meaning. The two senses below simply separate who is doing the dwelling: God taking up residence among people, and created beings who already live in heaven. The difference lies in the subject and the setting, not in the word.