Faint - Vine's Expository Dictionary of New Testament Words
Faint
[ 1,,G1590, ekluo ]denotes
(a) to loose, release" (ek, "out," luo, "to loose");
(b) "to unloose," as a bow-string, "to relax," and so, "to enfeeble," and is used in the Passive Voice with the significance "to be faint, grow weary,"
(1) of the body, Matthew 15:32; (some mss. have it in Matthew 9:36); Mark 8:3;
(2) of the soul, Galatians 6:9 (last clause), in discharging responsibilities in obedience to the Lord; in Hebrews 12:3, of becoming weary in the strife against sin; in Hebrews 12:5, under the chastening hand of God. It expresses the opposite of anazonnumi, "to gird up," 1 Peter 1:13.
[ 2,,G1573,enkakeo / ekkakeo ] "to lack courage, lose heart, be fainthearted" (en, "in," kakos, "base"), is said of prayer, Luke 18:1; of Gospel ministry, 2 Corinthians 4:1, 2 Corinthians 4:16; of the effect of tribulation, Ephesians 3:13; as to well doing, 2 Thessalonians 3:13, "be not weary" (AV marg., "faint not"). Some mss. have this word in Galatians 6:9 (No. 1).
[ 3,,G2577, kamno ]
primarily signified "to work;" then, as the effect of continued labor, "to be weary;" it is used in Hebrews 12:3, of becoming "weary" (See also No. 1), RV, "wax not weary;" in James 5:15, of sickness; some mss. have it in Revelation 2:3, AV, "hast (not) fainted," RV, "grown weary." See SICK, WEARY.
Note: For apopsucho, Luke 21:26, RV, See FAIL, Note
(3).