to slaughter an animal as an offering to a god; to sacrifice.
At its root this word names a single physical act: killing an animal so that it can be given to a deity. It is not a general word for killing, and it is not a word for burning an offering whole. It pictures the kind of sacrifice that ends in a shared meal, where part of the animal goes to the god and the rest is eaten by the worshippers. That is why the word so often stands close to feasting, vows, and festivals.
The Bible uses the word in two opposite directions, and the difference is not in the act but in who receives it. Done toward the LORD at the place he chose, it is the heart of right worship. Done toward other gods, idols, or local shrines, the very same act becomes Israel's signature sin. The prophets and the historians of the kings keep score with this word: a king who sacrificed to the LORD against one who sacrificed at the high places or to the Baals.
A smaller group of uses drops the religious setting altogether and means simply to slaughter an animal for food. The law that allowed ordinary, non-altar slaughter once Israel spread across the land uses this word for it, treating butchering for the table as a plain, permitted act rather than worship.
Because the word can name both faithful worship and idolatry, the prophets also use it to expose worship that is going through the motions. To sacrifice is good, they insist, only when the heart and the life match the act; otherwise the slaughter counts for nothing.