anger: hot, flaring displeasure, of God or of a person.
This is the Bible's most common word for anger, and most of its uses point to God. The picture behind it is physical. The same word names the nose, and an angry person was seen as one whose nose grows hot and flares, the way breathing quickens and the nostrils widen in a burst of temper. So the word does not describe a cool, settled disposition. It pictures heat flaring up, which is why it so often travels with words for burning and kindling.
When the anger is God's, it is never a fit of temper. It is his settled, righteous response to sin and covenant-breaking, real and fearful but answerable to his justice and his mercy. The Bible holds the two together: the God whose anger burns against rebellion is the same God who is famously slow to anger and quick to relent. God's anger is often pictured as heat that leaves the body, smoke and fire streaming from his nostrils, while a person's anger stays as heat inside. When the anger is a person's, the range runs from righteous indignation to sinful rage, and the wisdom writings warn against the hot-tempered person and praise the one who is hard to provoke.
Because the word is so tied to the image of the flaring nostril, Hebrew built two opposite expressions on it. To be short of nose is to be quick-tempered, and to be long of nose is to be patient and slow to anger. The second of these became one of the Bible's central descriptions of God's own character.