min (prefix “between”) + sîr (“river”) + ath (class plural suffix)
noun. between the rivers
place name. Between the Rivers
Region between the Baranduin and the Gwathló (LotR/1040), translated “Between the Rivers” (UT/261), a combination of mîn “between” (VT47/11, 14), the lenited form of sîr “river” (SA/sîr) and the class-plural suffix -ath.
Word Gloss mîn “[thing] between; gap, space, barrier; anything intervening between two other things” sîr “river, stream” -ath “collective or group plural”