to despise: to treat someone or something as worthless and beneath respect.
At its core this word is a judgment of worth. To do it is to size something up and rate it as nothing, then to act as though that verdict were true. It is not a flash of anger but a settled low estimate that shows itself in how a person treats what they look down on.
The same verb covers both sides of contempt. On the active side, a person, a nation, or even God is the one who scorns: Esau shrugs off his birthright, an enemy sneers at a young David, a wife sneers at a dancing king. On the receiving side, the word turns into a description of the one who is looked down on, the despised and rejected figure, the man treated as a worm and not a person. The shame in those passages is exactly the shame of being counted worthless by others.
A particular and serious use is despising God or what belongs to him. To despise the LORD's word, his name, his oath, or his holy things is treated as a grave offense, the inner attitude behind open rebellion. So the word reaches from a careless shrug at a meal to the deliberate scorn that breaks faith with God.