Long-tempered endurance — the opposite of short-tempered anger. The word is a compound: makros (long) + thumos (passion/wrath). God's makrothumia is his patience with sinners (2 Pet 3:9).
Included in both the fruit of the Spirit (Gal 5:22) and God's own character (Rom 2:4). The NT explains history's length as a form of divine makrothumia — God giving time for repentance before judgment.
God's makrothumia toward sinners is the reason the present age continues. 2 Peter 3:15 says to 'count the patience [makrothumia] of our Lord as salvation' — his delay is grace, not absence.