Jera (also Jeran, Jeraz) is the conventional name of the j-rune ᛃ of the Elder Futhark, from a reconstructed Common Germanic stem *jēra- meaning "harvest, (good) year".
The corresponding letter of the Gothic alphabet is Gothic 𐌾, named jēr, also expressing /j/. The Elder Futhark rune gives rise to the Anglo-Frisian runes ᛄ /j/, named gēr /jeːr/, and ᛡ /io/, named ior, and to the Younger Futhark ár rune ᛅ, which stood for /a/ as the /j/ phoneme had disappeared in Old Norse.
The reconstructed Common Germanic name *jēran is the origin of English year (Old English ġēar). In contrast to the modern word, it had a meaning of "season" and specifically "harvest", and hence "plenty, prosperity".
The Germanic word is cognate with Greek ὧρος (horos) "year" (and ὥρα (hora) "season", whence hour), Slavonic jarŭ "spring" and with the -or- in Latin hornus "of this year" (from *ho-jōrinus), as well as Avestan yāre "year", all from a PIE stem *yer-o-.
The derivation of the rune is uncertain; some scholars see it as a modification of Latin G ("C (ᚲ) with stroke") while others consider it a Germanic innovation. The letter in any case appears from the very earliest runic inscriptions, figuring on the Vimose comb inscription, harja.