From BiblePortal Wikipedia

Hastings' Dictionary of the Bible [1]

LAHMI . The brother of Goliath the Gittite, slain by Elhanan the son of Jair (  1 Chronicles 20:5 ). There is a discrepancy between this passage and the parallel passage in   2 Samuel 21:19 , where we read that ‘Elhanan [wh. see] the Bethlehemite slew Goliath the Gittite.’ If the text of Chronicles is the more correct, the designation Bethlehemite of Samuel is simply a corruption of the name Lahmi , but the converse might also be the case.

T. A. Moxon.

Smith's Bible Dictionary [2]

Lah'mi. (Warrior). The brother of Goliath, the Gittite, slain by Elhanan, the son of Zair or Zaor.  1 Chronicles 20:5. (B.C. 1020).

Holman Bible Dictionary [3]

 1 Chronicles 20:5 2 Samuel 21:19 1 Samuel 17:1

Fausset's Bible Dictionary [4]

 1 Chronicles 20:5. (See Elhanan ; Jaare Oregim )  2 Samuel 21:19.

Morrish Bible Dictionary [5]

Brother of Goliath, killed by Elhanan.  1 Chronicles 20:5 .

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [6]

(Heb. Lachmi', לִחְמַי , My Bread; Septuag. Λεεμεί v. r. Λοομί , Λαχμί , etc.; Vulg. Bethlehemites), a person named ( 1 Chronicles 20:5) as being the brother of (Goliath, and slain by Elhanan, one of David's heroes; but prob. a corrupt reading for Beth-Lehemite as in the parallel passage ( 2 Samuel 21:19). (See Elhanan). It wouldi seem that both these passages should be restored so as to read thus: " Elhanan, the son of Jair (or Dodo) of Bethlehem, slew the brother of Goliath of CGath, whose spear-handle was like a weaver's beam." (See Jair).

International Standard Bible Encyclopedia [7]

la´mı̄ ( לחמי , laḥmı̄ ): According to   1 Chronicles 20:5 , the brother of Goliath of Gath. See El-Hanan .