From BiblePortal Wikipedia

Holman Bible Dictionary [1]

 1 Samuel 20:26Jair

Morrish Bible Dictionary [2]

Designation of Ira, a ruler under David.  2 Samuel 20:26 .

International Standard Bible Encyclopedia [3]

jā´ẽr - ı̄t ( יארי , yā'irı̄ , "of Jair"): In   2 Samuel 20:26 , Ira the Jairite is "chief minister unto David." He was a descendant of Jair who was a Manassite ( Numbers 32:41 , etc.) and whose territory was in Gilead. Septuagint, Lucian, and Syriac suggest יתּרי , yattirı̄ , "Jattirite," i.e. a native of Jattir mentioned in  1 Samuel 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  2 Samuel 23:38 .