twelve: the cardinal number 12
At its core this is simply the number twelve, used the way any number is used: twelve years, twelve baskets, twelve hours in a day. Most of its uses are this plain count, and nothing more should be read into them.
But twelve carries weight in the Bible that, say, eleven or thirteen do not, because Israel was built on twelve tribes descended from the twelve sons of Jacob. So when the writers reach for twelve in connection with God's people, the number itself is doing work: it signals the whole people, complete and rightly ordered. Jesus chooses exactly twelve close followers, and the Gospels quickly turn that count into a title, "the Twelve," naming the group rather than counting heads. The number says that this circle stands for the renewed Israel.
That same logic runs through the last book of the Bible, where the new Jerusalem has twelve gates named for the twelve tribes and twelve foundations named for the twelve apostles. The senses below separate the plain count from these loaded uses, but they are one word with one meaning: the reader has to watch the context to tell when twelve is just a number and when it is pointing to the people of God.