From BiblePortal Wikipedia

Smith's Bible Dictionary [1]

Na'ham. (Consolation). The brother of Modiah or Jehudiah, wife of Ezra.  1 Chronicles 4:19.

Hastings' Dictionary of the Bible [2]

Naham The father of Keilah (  1 Chronicles 4:19 ).

Morrish Bible Dictionary [3]

A man of Judah, father of Keilah and Eshtemoa.  1 Chronicles 4:19 .

Holman Bible Dictionary [4]

 1 Chronicles 4:19

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [5]

(Heb. Naclh'am, נִחִם , Consolation; Sept. Ναχέμ v. r. Ναχα Μ , Ναχέθ ), a brother of Holiah, the second or Jewish wife of Mered; and "father" of Keilah and Eshtemoa ( 1 Chronicles 4:19). B.C. post 1612. He seems to have been the same called ISHBAH (See Ishbah) (q.v.) in  1 Chronicles 4:17. (See Mered).

International Standard Bible Encyclopedia [6]

nā´ham ( נחם , naḥam , "comfort"): A J udahite chieftain, father of Keilah the Garmite  1 Chronicles 4:19; the passage is obscure.