JAIRITE jā’ ə rīt (הַיָּ֣אִרִ֔י, of Jair). A gentilic used for Ira the priest of David, showing that he was descended from Jair (1), the son of Manasseh (Num 32:41; Deut 3:14).

International Standard Bible Encyclopedia (1915)

In 2Sa 20:26, Ira the Jairite is "chief minister unto David." He was a descendant of Jair who was a Manassite (Nu 32:41, etc.) and whose territory was in Gilead. Septuagint, Lucian, and Syriac suggest yattiri, "Jattirite," i.e. a native of Jattir mentioned in 1Sa 30:27 as one of the towns friendly to David when he was in Ziklag. It is not improbable that a native of Jattir would be given such a post by David.

See [[Ira]], and compare 2Sa 23:38.