What does advantage mean?
The definition of advantage
Ad*van”tage, n.
Etym: [OE. avantage, avauntage, F. avantage, fr. avant before. See Advance, and cf. Vantage.]

1 Any condition, circumstance, opportunity, or means, particularly favorable to success, or to any desired end; benefit; as, the enemy had the advantage of a more elevated position. Give me advantage of some brief discourse. Shak. The advantages of a close alliance. Macaulay.
2 Superiority; mastery; — with of or over. Lest Satan should get an advantage of us. 2 Cor. ii. 11.
3 Superiority of state, or that which gives it; benefit; gain; profit; as, the advantage of a good constitution.
4 Interest of money; increase; overplus (as the thirteenth in the baker’s dozen). [Obs.] And with advantage means to pay thy love. Shak. Advantage ground, vantage ground. [R.] Clarendon.

— To have the advantage of (any one), to have a personal knowledge of one who does not have a reciprocal knowledge. “You have the advantage of me; I don’t remember ever to have had the honor.” Sheridan.
— To take advantage of, to profit by; (often used in a bad sense) to overreach, to outwit.
Synonyms
— Advantage, Advantageous, Benefit, Beneficial. We speak of a thing as a benefit, or as beneficial, when it is simply productive of good; as, the benefits of early discipline; the beneficial effects of adversity. We speak of a thing as an advantage, or as advantageous, when it affords us the means of getting forward, and places us on a “vantage ground” for further effort. Hence, there is a difference between the benefits and the advantages of early education; between a beneficial and an advantageous investment of money.

Ad*van”tage, v. t.
[imp. & p. p. Advantaged; p. pr. & vb. n.Advantaging.]
Etym: [F. avantager, fr. avantage. See Advance.]

To give an advantage to; to further; to promote; to benefit; to profit. The truth is, the archbishop’s own stiffness and averseness to comply with the court designs, advantaged his adversaries against him. Fuller. What is a man advantaged, if he gain the whole world, and lose himself, or be cast away Luke ix. 25. To advantage one’s self of, to avail one’s self of. [Obs.]