HAPAX LEGOMENA (Gr. "once said"), words which are only once recorded in a certain kind of literature. Since the interest in Middle Hebrew lexicography arose comparatively late, Middle Hebrew texts are frequently not well-established philologically and new texts are often discovered, the interest in hapax legomena in Hebrew is, for all practical purposes, limited to the Bible or, more precisely, to biblical Hebrew. There are in biblical Hebrew about 1,300 hapax legomena (yet their precise number cannot be stated, since the exact definition is not clear as to whether or not they include homonymic hapax legomena). Most of them (about 900) are not too difficult to interpret, being derived from well-known biblical roots (as emdah, Micah 1:11, moomad, Ps. 69:3, both denoting "standing ground," being derived from the well-known root dmA, "to stand"). About 400, however, cannot be derived from known biblical roots and are therefore more difficult to interpret. Occurring only once, their exact meaning is more difficult to establish from context than that of words attested more often. Except for this fact and the possibility that hapax legomena may have arisen through error in transmission, the philological treatment of hapax legomena does not differ from that of words occurring more often. The meaning of both is elucidated by comparison with other Semitic languages, which often makes it possible to establish the etymology of the word treated. Middle Hebrew has, of course, a special standing in this matter. Since the Bible, because of its small size and limited topics, has preserved only a small part of Hebrew vocabulary, it is often due to mere chance that a word occurs only once in the Bible, though there may be ample examples of it in Middle Hebrew (as in the case with sullam "ladder," Gen. 28:12). Even the sages of the Mishnah did not understand the hapax legomenon we-tetetiha, "and I will sweep it" (Isa. 14:23), except with the help of vernacular speech, as used by Rabbi's handmaid (RH 26b). Hapax legomena sometimes belong to removed subject matters (as Isa. 3:18ff., describing the ornaments of Zion's daughters), and there are relatively many hapax legomena denoting animals, plants, and diseases (as leta$ah "lizard," Lev. 11:30; luz, "almond tree," Gen. 30:37; harhur, "fever," Deut. 28:22) and loan words (as appiryon, "litter," Song 3:9). The Book of Job, with its special style and many Aramaisms, contains a relatively large proportion of hapax legomena, 145 in number, among them 60 without derivation from known biblical roots. The (much larger) Book of Isaiah has 201 hapax legomena, among them, again, 60 without derivation.
In Hebrew literature hapax legomena are called en lo ah, en lo haver, en lo rea ba-Miqra, "it has nothing alike, no brother, no fellow, no comrade in the Bible," or millim bodedot, "isolated words." Saadiah Gaon wrote in Arabic Kitab al-Sabin Lafza min Mufradat al-Quran ("The Book of Seventy Hapax Legomena in the Bible"), dealing with over 90 (!) hapax legomena, which he explains by means of mishnaic words. It stands to reason that this book originally contained 70 words, and was expanded later, either by Saadiah himself or by others, yet preserving its original name. Although it is one of the oldest and most important philological works in the history of Hebrew linguistics, it is in its intention a polemic work against Karaites, endeavoring to prove the value of tradition from the linguistic point of view: without mishnaic Hebrew even the linguistic interpretation of the Bible is impossible.