From BiblePortal Wikipedia

Hawker's Poor Man's Concordance And Dictionary [1]

One of the sons of Elimelech,  Ruth 1:2. His name is derived from Mahol, infirmity. Perhaps the father's name, and the whole family were figurative. In the history of this house, we read that in the days when the Judges ruled, there was a famine in the land. The Book of the Judges, at the close, saith, that in those days, "there was no king in Israel, every man did that which was right in his own eyes." ( Judges 21:25) And this we may be sure, was bad enough. In such seasons there is always a famine, not perhaps of bread and water, but a famine to the soul in not hearing the word of the Lord. ( Amos 8:11) In this state this house in Israel left Bethlehem-Judah, the land of bread, and the bread of JEHUDAH, (for so Bethlehem-Judah means) and went to sojourn in Moab. In other words, left the Lord to seek the world in Moab. To this history correspond the names. Elimelech signifies, my God, a king. Naomi, my pleasant one; now called Marah, bitterness; and Mahlon and Chillon, sickness and consumption.

Smith's Bible Dictionary [2]

Mah'lon. (Sick). The first husband of Ruth; son of Eiimelech and Naomi.  Ruth 1:2;  Ruth 1:5;  Ruth 4:9-10. Compare  1 Samuel 17:12.

Fausset's Bible Dictionary [3]

Ruth's first husband ( Ruth 1:2;  Ruth 1:5;  Ruth 4:9). An Ephrathite of Bethlehem Judah, son of Elimelech and Naomi. Mahlon died in Moab childless, a judgment says the Targum for his marrying a Moabitess.

Morrish Bible Dictionary [4]

Son of Elimelech and Naomi, and husband of Ruth.  Ruth 1:2,5;  Ruth 4:9,10 .

Holman Bible Dictionary [5]

 Ruth 1:2 1:5 Ruth 4:9-10

American Tract Society Bible Dictionary [6]

A son of Elimelech and Naomi, and the first husband of Ruth the Moabites,  Ruth 1:1-22 .

Easton's Bible Dictionary [7]

 Ruth 1:2,5 4:9,10

Hastings' Dictionary of the Bible [8]

MAHLON. See Chilion.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [9]

(Hebrew Alachlon', מִחְלוֹן , Sickly; Sept. Μααλών , Vulg. Mahalon ) , the elder of the two sons of Elimelech the Bethlehemite by Naomi; they removed with him to Moab, where this one married Ruth, and died childless ( Ruth 1:2;  Ruth 1:5;  Ruth 4:9-10). B.C. cir. 1360. (See Ruth). "It is uncertain which was the elder of the two. In the narrative ( Ruth 1:2;  Ruth 1:5) Mahlon is mentioned first, but in his formal address to the elders in the gate ( Ruth 4:9), Boaz says Chilion and Mahlon.' Like his brother, Mahlon died in the land of Moab without offspring, which in the Targum on Ruth ( Ruth 1:5) is explained to have been a judgment for their transgression of the law in marrying a Moabitess. In the Targum on  1 Chronicles 4:22, Mahlon is identified with Joash, possibly on account of the double meaning of the Hebrew word which follows, and which signifies both had dominion' and married.'

International Standard Bible Encyclopedia [10]

ma´lon ( מחלון , maḥlōn , "invalid"): Ruth's first husband (  Ruth 12,5; Rth 4:9, Rth 4:10). In the latter passage is further evidence of the unwillingness to allow a family connection or inheritance to drop (see Mahlah; Mahli ). Note that David's descent and that of his "Greater Son" come through Ruth and Boaz (Rth 4:22).

Kitto's Popular Cyclopedia of Biblial Literature [11]

Mah´lon, one of the two sons of Elimelech and Naomi, and first husband of Ruth the Moabitess (, sq.) [RUTH].