From BiblePortal Wikipedia

Webster's Dictionary [1]

(1): ( v.) A flat roof to a house; as, the buildings of the Oriental nations are covered with terraces.

(2): ( v.) A street, or a row of houses, on a bank or the side of a hill; hence, any street, or row of houses.

(3): ( v.) A balcony, especially a large and uncovered one.

(4): ( v.) A raised level space, shelf, or platform of earth, supported on one or more sides by a wall, a bank of tuft, or the like, whether designed for use or pleasure.

(5): ( v.) A level plain, usually with a steep front, bordering a river, a lake, or sometimes the sea.

(6): ( v. t.) To form into a terrace or terraces; to furnish with a terrace or terraces, as, to terrace a garden, or a building.

Holman Bible Dictionary [2]

 2 Chronicles 9:11

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [3]

( מְסַלָּה , Mesillah,  2 Chronicles 9:11; Sept. Ἀνάβασις ; a Highway, as elsewhere usually rendered), a staircase, constructed by Solomon for his edifices out of the algum-trees imported from the East Indies. (See Palace); (See Temple).

International Standard Bible Encyclopedia [4]

ter´ā́s ( מסלּה , meṣillāh ): Solomon is said, in   2 Chronicles 9:11 , to have made of the algum trees brought him from Ophir "terraces," or raised walks, for the house of Yahweh. In the parallel  1 Kings 10:12 , the word used is rendered "pillars," margin "'a railing'; Hebrew 'a prop.'"