What does "sage" mean?

Additional senses

1. 2.Proceeding from wisdom; well judged; shrewd; well adapted to the purpose. Commanders, who, cloaking their fear under show of sage advice, counseled the general to retreat. Milton.
2. 3.Grave; serious; solemn. [R.] "[Great bards.] in sage and solemn tunes have sung." Milton.
3. 4.A wise man; a man of gravity and wisdom; especially, a man venerable for years, and of sound judgment and prudence; a grave philosopher. At his birth a star, Unseen before in heaven, proclaims him come, And guides the Eastern sages. Milton.