to mourn: to grieve a loss so deeply that the sorrow shows
This is grief that has gone public. It is the word for what the bereaved do, and in the New Testament it hardly ever stands alone: over and over it is joined to weeping (κλαίω), so that mourning names the whole condition of a grieving person while weeping names the sound that condition makes. Dust on the head, torn clothes, a household that stops its ordinary business: this is the sorrow of someone who has lost something real, and everyone around can see it.
From the funeral the word travels outward, and each of its uses keeps that same weight of real loss:
- the grief of the bereaved, and the settled mourning a death lays on a household
- the wail raised over a ruined city by the merchants who watch their fortune burn
- the sorrow a church owes over sin it has quietly tolerated
- the mourning Jesus blesses, and the mourning he warns is coming for the comfortable
What holds these together is that something has genuinely been lost, and mourning is the honest answer to it. That is why the word keeps turning up as the exact opposite of laughter, feasting, and a wedding: you cannot celebrate and mourn at the same time, so the presence of one announces the absence of the other. It is also why the apostles can demand it. If a community has lost its integrity, the fitting response is not embarrassment but grief.
The word is worth distinguishing from the inward ache of a hurt heart (λυπέω). That pain can stay hidden, and one person can inflict it on another. Mourning here is the sorrow you can see, the state a person is publicly in, and the New Testament attaches a promise to it: those who mourn now are exactly the ones who will be comforted.