From BiblePortal Wikipedia

Fausset's Bible Dictionary [1]

( 2 Chronicles 2:8;  2 Chronicles 9:10-11) (ALMUG  1 Kings 10:11). From the Arabic article Al and Mica , "red sandalwood," or Sanskrit Valgu , in the Deccan Valgum , "sandalwood." Brought from Ophir, and from Lebanon. Used for pillars and stairs in the Lord's house and the king's house, and for harps and psalteries. The cedars and firs came from Lebanon, but the almug trees from Ophir, an Arabian mart on the Red Sea, for eastern produce intended for Tyre and the W. The algums would come with the firs and cedars cut from Lebanon, and so all would be described collectively as "from Lebanon." The red sandalwood of China and India still used for making costly utensils. Else, the common sandalwood ( Santalum Album of Malabar coast), outside white and without odor, but within and near the root fragrant, fine grained, and employed still for fancy boxes and cabinets, and used as incense by the Chinese.

Smith's Bible Dictionary [2]

Algum or Almug Trees. Algum . Occurring in  2 Chronicles 2:8;  2 Chronicles 9:10-11 and Almug Trees appearing in  1 Kings 10:11-12. These words are identical. From  1 Kings 10:11-12;  2 Chronicles 9:10-11, we learn that the almug was brought in great plenty from Ophir for Solomon's Temple and house, and for the construction of musical instruments.

It is probable that this tree is the Red Sandal Wood, which is a native of India and Ceylon. The wood is very heavy, hard and fine grained, and of a beautiful garnet color.

King James Dictionary [3]

AL'GUM, n. In scripture, a tree or wood about which the learned are not agreed. The most probably conjecture is that the word denotes gummy or resinous wood in general.

The Vulgate translates it ligna thyina, and the Septuagint, wrought-wood others, ebony, bravil or pine, and the Rabbins render it coral. It was used for musical instruments, stair cases, &c.

The thyinum is the citron tree, from Mauritania, much esteemed by the ancients for its fragrance and beauty. The almug, almugim, or algumin, or simply gummin is most probably a gummy wood, and perhaps may be the Shittim, often mentioned in Scripture. See  1 Kings 10:11 .

Watson's Biblical & Theological Dictionary [4]

אלגם or אלגומים ,  1 Kings 10:11-12 . This is the name of a kind of wood, or tree, large quantities of which were brought by the fleet of Solomon from Ophir, of which he made pillars for the house of the Lord, and for his own palace; also musical instruments. See Almug .

Holman Bible Dictionary [5]

 2 Chronicles 2:8 1 Kings 10:11-12  2 Chronicles 9:10-11

Webster's Dictionary [6]

(1): (n.) Same as Almug (and etymologically preferable).

(2): (n.) A tree or wood of the Bible (2 Chron. ii. 8; 1 K. x. 11).

Easton's Bible Dictionary [7]

 2 Chronicles 2:8 9:10,11 1 Kings 10:11

People's Dictionary of the Bible [8]

Algum.  2 Chronicles 2:8. See Almug.

American Tract Society Bible Dictionary [9]

The same as Almug , which see.

Hastings' Dictionary of the Bible [10]

ALGUM . See Almug.

Kitto's Popular Cyclopedia of Biblial Literature [11]

Al´gum, or Al´mug Trees ( 1 Kings 10:11;  2 Chronicles 9:10-11). With regard to Ophir, the place from which these trees were brought to us, there appears no doubt that it was to the southward of the Red Sea, and was most probably in some part of India. Various trees have been attempted to be identified with the almug, but the balance of evidence seems to be in favor of the sandal-wood, which is known and highly esteemed in India. The tree which produces it is a native of the mountainous parts of the coast of Malabar, where large quantities are cut for export to China, to different parts of India, and to the Persian and Arabian gulfs. The outer parts of this tree are white and without odor; the parts near the root are most fragrant, especially of such trees as grow in hilly situations and stony ground. The trees vary in diameter from 9 inches to a foot, and are about 25 or 30 feet in height, but the stems soon begin to branch. This wood is white, fine-grained, and agreeably fragrant, and is much employed for making rosaries, fans, elegant boxes, and cabinets.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [12]

a transposed form ( 2 Chronicles 2:8;  2 Chronicles 9:10-11) of the Hebrew term ALMUG (See Almug) (q.v.).