The Hebrew noun be'ushim (plural) refers to wild, worthless, or stinking grapes — the bitter, inedible fruit that a neglected or corrupt vine produces instead of good grapes. It appears in Isaiah 5 in the famous parable of the vineyard.
Isaiah 5's parable of the vineyard is one of the most powerful in the Old Testament: God planted Israel as His choice vine, expecting justice and righteousness, but found only the wild, worthless grapes of injustice and bloodshed. The contrast between expected fruit and actual be'ushim captures the tragedy of covenant unfaithfulness. Jesus echoes this parable in Mark 12, applying it to the religious leaders of His day. The New Testament response is the true vine (John 15) — Christ Himself who bears the fruit the old vineyard could not produce.