Lexicon :: Strong's G2756 - kenos

κενός, κενή, κενόν (from Homer on down), the Sept. for רֵיקָם, רֵק, רִיק, etc., empty;
1. properly, of places, vessels, etc.,which contain nothing (Judges 7:16; Genesis 37:24); metaphorically, empty, vain; devoid of truth: λόγοι, Ephesians 5:6 (Exodus 5:9); ἀπάτη, Colossians 2:8; κήρυγμα, πίστις, 1 Corinthians 15:14.
2. of men, empty-handed; without a gift: ἀποστέλλειν and ἐξαποστέλλειν τινα κενόν (Genesis 31:42; Deuteronomy 15:13; Deuteronomy 16:16), Mark 12:3; Luke 1:53; Luke 20:10f; metaphorically, destitute of spiritual wealth, of one who boasts of his faith as a transcendent possession, yet is without the fruits of faith, James 2:20.
3. metaphorically, of endeavors, labors, acts, which result in nothing, vain, fruitless, without effect: ἡ χάρις, 1 Corinthians 15:10; κόπος; 1 Corinthians 15:58; ἡ εἴσοδος, 1 Thessalonians 2:1; neuter plural κενά, things that will not succeed, Acts 4:25 (from Psalm 2:1); εἰς κενόν, in vain, to no purpose (cf. Winer's Grammar, 592 (551)): 2 Corinthians 6:1; Galatians 2:2; Philippians 2:16; 1 Thessalonians 3:5 (Isaiah 65:23; Jeremiah 6:29, etc.; Diodorus 19, 9; Heliodorus 10, 30). (Cf. Trench, Synonyms, § xlix.)

BLB Scripture Index of Thayer's