breathed out by God: produced by God's own breath, said of Scripture
This word appears only once in the Bible, when Paul tells Timothy that all Scripture is theopneustos. It is a made-up compound, joining the word for "God" to the word for "breathing," and it means that what God breathes is where Scripture comes from. The picture is not of God reacting to a book someone else wrote, but of God breathing the words out, the way a person's breath carries their speech. The point of the word is the origin of Scripture: it traces back to God himself.
The shape of the word points to something God did, not something Scripture does on its own. So the most careful sense is passive: Scripture is breathed out by God, not breathing God out. That is the reading the ancient church writers settled on and the standard reference works follow today.
At the same time, the breath in view is the same breath the Bible elsewhere uses for the breath of life (נשׁמה), the breath God blew into the first human and that animates living things. So a faithful reading hears more than a bare claim about where the words came from. The same breath that gave life can still give life through these texts, which is exactly why Paul goes on to call Scripture useful for teaching, correcting, and training. The word claims that Scripture comes from God; it does not, by itself, settle the harder questions of how God worked through the human writers.