a matched pair: two animals or riders taken together, especially a team of oxen joined at a single yoke
TranslatabilityApproximateCertaintySettled
At its heart this word names two of something joined into one working unit. The clearest case is a team of oxen: two animals harnessed side by side to a single yoke so they pull as one. Counting cattle by this pair became so ordinary that a wealthy man's herds are tallied in it, as when Job is said to own five hundred of these teams.
The same word also counts other animals and riders simply as a matched set: a couple of saddled donkeys loaded for a journey, two mules carrying a load of soil, or the pair of horsemen a lookout spots riding toward him. In every case the point is twoness held together, whether the two are strapped to one yoke or just moving as a pair.
English has to shift words to follow it, saying "yoke" for the oxen but "pair" or "couple" for the donkeys and riders, so the single Hebrew idea of two bound into one unit is easy to lose sight of.
Nuances
1aa yoke of oxen: two oxen harnessed together to pull a plow or cart, and the unit for counting cattle in pairs
an acre: a measure of farmland, as much ground as a yoke of oxen could plow in a day
TranslatabilityApproximateCertaintyStrong
Because a single yoke of oxen could turn a fairly predictable strip of ground in a day's work, the same word came to name that patch of land itself, much as older English once measured a field by what a team could plow between sunrise and sunset. So when a harvest is measured out, ten of these plots of vineyard yield only a little wine, and a battlefield is sized as about half of one such plot of ground.
This is a rough, working measure, not a surveyor's figure. Its size depended on the soil, the season, and the animals, so it is best understood as roughly a day's plowing rather than any fixed area.
It names a matched pair or team of working animals harnessed together, most often a yoke of oxen for plowing.1Sa 11:71Ki 19:19Job 1:3
It can also be a couple of riders or their mounts moving as a set, such as a pair of saddled donkeys or a pair of horsemen.Jdg 19:102Sa 16:1Isa 21:7
It serves as a measure of farmland, the acre being as much ground as one team plows in a day.1Sa 14:14Isa 5:10
Both
Both belong to the single scene of oxen harnessed for field work: one word names the team that pulls, the other the bar they pull under.Num 19:2Jer 51:23
It names the wooden yoke-bar itself, the implement laid across an animal's neck to harness it for work.Num 19:21Sa 6:7
It stands for imposed servitude and bondage, the burden of subjection a conqueror or master lays on a people, whose lifting pictures liberation.Gen 27:40Lev 26:131Ki 12:4Jer 27:8
צָמַדthe root verb "to join or harness together," the action from which this noun for a joined pair is formed
tsemed in the other biblical languages
ζεῦγοςGreek“a yoke/pair”the Greek word for a yoke or pair, used both for a pair of doves and for five yoke of oxen
Reaches beyond draft animals to any counted pair, including a matched set of birds: the pair of turtledoves brought as the temple offering.Luk 2:24
What scholars say about tsemed
The lexica (BDB, HALOT) derive the noun from the root צמד "to bind, join," and recognize two senses: a couple or yoke (of oxen, asses, horsemen) and, by metonymy, the acre as the area a yoke of oxen plows in a day (1 Samuel 14:14;Isaiah 5:10). The metrological sense parallels the Akkadian and later usage in which land is measured by a team's daily plowing; the exact area is not fixed and is estimated only approximately.