Meekness is the bridle of anger or wrath; the meek man is slow to wrath. He is one that does not soon take offence, and keeps such a command over his passion, that it does not unreasonably and violently break out, breaking up as it were the doors of his soul and flying forth and raging. The excellency of this is, that such a one is an understanding man, of great understanding. Worldly men, whose pride and passion is to them instead of law and reason, count such a one a poor mean-spirited, silly man, that does not understand himself; for that when he receives an injury, he does not presently take fire and resent it: but as the understanding, so the wisdom of the world is foolishness with God; and the world's fool is God's wise man.
Thomas Boston The Works of Thomas Boston (Vol. 5, pg. 150)
Meekness is showing patience and humility. A calm temper of mind, that is not easily provoked The cultivation of this spirit is enjoined (Col. 3:12; 1 Tim. 6:11; Zeph. 2:3), and is exemplified in: Christ (Matt. 11:29), Abraham (Gen. 13; 16:5, 6), Moses (Num. 12:3), David (Zech. 12:8; 2 Sam. 16:10, 12), Paul (1 Cor. 9:19). Special promises are made to the meek (Matt. 5:5; Isa. 66:2).