pain or suffering, whether felt in the body or in the heart
This is the Bible's word for pain in its fullest reach: the ache of a sick body, the sting of a wound, and the heavier weight of grief and heartache. It is built on a root that simply means to hurt, and it names the hurt itself, wherever it is felt.
Hebrew does not force the split that English makes between physical pain and emotional pain. The same word describes a man broken on his sickbed and a mourner whose grief has no equal, because to the biblical writers both are one thing: suffering. That is why translations reach for different words, "pain," "sorrow," "grief," "suffering," depending on the verse, while the Hebrew holds them together. A close cousin from the same root, כְּאֵב, leans toward the raw ache of pain, and this word toward the whole experience of suffering it brings.
The word gathers its deepest force in Isaiah's picture of the servant as a "man of sorrows" who carries the pain of others, and in Lamentations, where a ruined city cries that no sorrow was ever like its sorrow.