Concise Bible Dictionary:
A title of the Lord Jesus, which He will bear in connection with Israel in the future (Isa. 4:2; Jer. 23:5; 33:15; Zech. 3:8; Zech. 6:12-13). In two of the passages the words “unto David” are added, which coincides with the Lord Jesus being the “offspring” (which is a similar word to “branch”) as well as the “root” of David. He will be a “righteous Branch and a King.” He will “build [or advance in honor] the temple of Jehovah; and he shall bear the glory, and shall sit and rule upon his throne; and he shall be a priest upon his throne: and the counsel of peace shall be between them both” (Compare Psa. 85 and 87). It is a description of the Lord Jesus in the millennium.