From BiblePortal Wikipedia

People's Dictionary of the Bible [1]

Methuselah ( Me-Thû'Se-Lah ), Man Of Dart, or He Dies And It Is Sent —namely, the flood. The son of Enoch, and, according to Hebrew chronology, 969 years old when he died, in the first year of the flood. The longest-lived man was the son of the saintliest of his time.  Genesis 5:27;  1 Chronicles 1:3. He lived 243 years with Adam and 600 years with Noah. The history of the fall and of the world before the flood was carried thus through only one person to Noah.

Fausset's Bible Dictionary [2]

("he dies and it (the flood) is sent".) A name given prophetically by Enoch, or given after the event. Phoenician inscriptions use Methu or Betha ("a man"). The man who lived the longest - 969 years. He died in the year of the flood, possibly by it. It is suggestive that death enters into the name of the longest liver. No record of godliness is given, as in his father Enoch's case ( Genesis 5:21-27); faith is not always hereditary.

Hastings' Dictionary of the Bible [3]

METHUSELAH. A Sethite, the father of Lamech,   Genesis 5:21 ff. (P [Note: Priestly Narrative.] ),   1 Chronicles 1:3 ,   Luke 3:37 = Methushael in J [Note: Jahwist.] ’s genealogy,   Luke 4:18 . The name is interpreted by Holzinger as ‘man of the javelin’ a fitting name for a time when the earth was full of violence.

Morrish Bible Dictionary [4]

Son of Enoch, and the seventh from Adam: he lived 969 years, longer than any other person, and died in the year of the flood.  Genesis 5:21-27;  1 Chronicles 1:3 . He is called Mathusala in  Luke 3:37 .

Watson's Biblical & Theological Dictionary [5]

the son of Enoch, and father of Lamech,  Genesis 5:21 . He was born A.M. 687 and died A.M. 1656, being the very year of the deluge, at the age of nine hundred and sixty-nine, the greatest age to which any mortal man ever attained.

Smith's Bible Dictionary [6]

Methu'selah. (Man Of The Dart). The son of Enoch, sixth in descent from Seth, and father of Lamech.  Genesis 5:25-27.

American Tract Society Bible Dictionary [7]

Son of Enoch, and father of Lamech. He lived 969 years, a longer life than any other on record, and died within the year before the deluge,  Genesis 5:21,22 .

Holman Bible Dictionary [8]

 Genesis 5:21 5:26-29 Genesis 5:27

Easton's Bible Dictionary [9]

 Genesis 5:21-27 1 Chronicles 1:3

Hastings' Dictionary of the New Testament [10]

METHUSELAH. —Mentioned as a link in our Lord’s genealogy,  Luke 3:37.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [11]

(Ieb. Methushe'lach, מְתוּשֵׁלִח , Man of the Dart ; Sept. and N.T. Μαθουσάλα ; Josephus, Μαθουσάλας , Ant. 1:3, 3 and 4; Vulg. Mathusala and Mathusale ; Auth. Vers. "Mathusala," in  Luke 3:37), the son of Enoch, and eighth of the Sethite antediluvian patriarchs (Genesis v. 21, 22, 25, 26, 27;  1 Chronicles 1:3). He was born (according to the Hebrews text) BC. 3484. When he had attained the age of 187 years, his son Lamech was born, after which he lived 782 years, and died (BC. 2516) only a few months before the flood, at the extreme age of 969; which, being the greatest term attained by any on record. has caused his name to become a proverb of long life. (See Longevity).

International Standard Bible Encyclopedia [12]

mḗ - thū´sḗ - la , me - thū´se - la ( מתוּשׁלח , methūshelaḥ , "man of the javelin"): A descendant of Seth, the son of Enoch, and father of Lamech (  Genesis 5:21 ff;   1 Chronicles 1:3;  Luke 3:37 ). Methuselah is said to have lived 969 years; he is therefore the oldest of the patriarchs and the oldest man. It is doubtful whether these long years do not include the duration of a family or clan.

Kitto's Popular Cyclopedia of Biblial Literature [13]

Methu´selah (man of the dust), son of Enoch, and remarkable as being the oldest of those antediluvian patriarchs whose great ages are recorded . At the age of 187 years he begat Lamech (the father of Noah); after which he lived 782 years, making altogether 969 years [LONGEVITY].