the grape harvest: the cutting of ripe grapes from the vines, the season when that is done, and the crop it brings in
This is the ordinary Hebrew word for bringing in the grapes. It looks at one event from more than one angle: the work of cutting the ripe clusters off the vines, the stretch of the year when that work is done, and the fruit that comes in as a result. English does the same thing with the word "harvest," which can name the job, the season, or the crop, so these shifts are not a sign of different words but of one word used naturally.
Two facts about the event itself give the word its force. First, it sat at a fixed place in the farming year, late summer into early autumn, after the grain had been cut (קָצִיר) and around the time everything was gathered in (אָסִיף). Leviticus 26:5 can therefore use it as a date: threshing that runs on until the grapes are cut, and grape cutting that runs on until sowing, is a picture of harvests so heavy they overlap. Second, the law told harvesters to leave what they missed on the vine for the poor and the foreigner, so a normal grape harvest ended with a few clusters still hanging (עֹלֵלוֹת).
The prophets work that second fact hard. To say a land is like the leftovers once the grapes have been cut (Isaiah 24:13), or that a man is like a gleaner who finds no cluster at all (Micah 7:1), is to say that almost nothing remains, and to a farmer that was a shocking claim, because a real harvest always left something. Gideon puts the same vocabulary to a very different use in Judges 8:2, rating another tribe's leftovers above his own clan's whole crop in order to flatter a rival and defuse a quarrel.
The same three letters also give the verb for cutting grapes and, more surprisingly, the words for walling a city off beyond reach (בָּצַר). Many standard dictionaries of Biblical Hebrew tie all of that to one underlying idea of cutting off, while others keep the grape word and the fortifying word apart as look-alikes. Either way, the connection is a reconstruction and not something a Hebrew reader would have heard in the word for the grape harvest.
Nuances
Whether בָּצִיר stands in Zechariah 11:2 at all. The consonantal text (Ketiv) reads בָּצוּר, a passive form of the root in its sense "inaccessible, fortified," while the Masoretic reading tradition (Qere) reads בָּצִיר "vintage."
- majorityRead the Ketiv בָּצוּר: the line laments the felling of an impenetrable forest, and the verse is not an occurrence of the noun "vintage" at all.; BDB, s.v. בָּצִיר, noting of Zechariah 11:2 "read בצור (Kt)"
- minorityRead the Qere בָּצִיר: the felled forest is described as a harvested one, and the verse counts as an occurrence of the noun.; Masoretic Qere at Zechariah 11:2, as printed in Biblia Hebraica Stuttgartensia