From BiblePortal Wikipedia

Smith's Bible Dictionary [1]

Ad'di. (Ornament)  Luke 3:28. Son of Cosam, and father of Melchi in our Lord's genealogy; the third above Salathiel.

Fausset's Bible Dictionary [2]

( Luke 3:28). In Jesus' genealogy. A shortened form of Adiel, or Adaiah, from Adi , "ornament."

Morrish Bible Dictionary [3]

Descendant of Cosam in the genealogy of the Lord Jesus.  Luke 3:28 . The name cannot be traced in the Old Testament.

Hastings' Dictionary of the Bible [4]

ADDI . An ancestor of Jesus,   Luke 3:28 .

Hastings' Dictionary of the New Testament [5]

ADDI. —An ancestor of Jesus Christ,  Luke 3:28.

Holman Bible Dictionary [6]

 Luke 3:28

Easton's Bible Dictionary [7]

 Luke 3:28

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [8]

( Ἀδδί , probably for Heb. Adi , עֲרַי , Ornament, as in  Exodus 33:4, etc.), the name of one or two men.

1. An Israelite, several of whose descendants on returning from Babylon, married heathen women ( 1 Esdras 9:31); for which the parallel text ( Ezra 10:30) has more correctly Pahath-Moab (See Pahath- Moab) (q.v.).

2. The son of Cosam and father of Melchi (i.e. probably Maaseiah,  2 Chronicles 34:8) in the maternal ancestry of Christ ( Luke 3:28). B.C. ante 623.

International Standard Bible Encyclopedia [9]

ad´ı̄ ( Ἀδδί , Addı́  ; Ἀδδεί , Addeı́ ): An ancestor of Joseph, the husband of Mary, mother of Jesus; fourth from Zerubbabel in the ascending genealogical series ( Luke 3:28 ).