From BiblePortal Wikipedia

Vine's Expository Dictionary of NT Words [1]

1: Εἴκοσι (Strong'S #1501 — Noun — eikosi — i'-kos-ee )

occurs in  Luke 14:31;  John 6:19;  Acts 1:15;  27:28;  1—Corinthians 10:8; of the "four and twenty" elders, in  Revelation 4:4 (twice),10; 5:8; 11:16; 19:4 (combined in one numeral with tessares, "four," in some mss.).

Webster's Dictionary [2]

(1): ( a.) An indefinite number more or less that twenty.

(2): ( a.) One more that nineteen; twice; as, twenty men.

(3): ( n.) The number next following nineteen; the sum of twelve and eight, or twice ten; twenty units or objects; a score.

(4): ( n.) A symbol representing twenty units, as 20, or xx.

King James Dictionary [3]

TWEN'TY, a. L. decem.

1. Twice ten as twenty men twenty years. 2. Proverbially, an indefinite number.

Maximilian, upon twenty respects, could not have been the man.