From a primary ollumi (to destroy; a prolonged form); ruin, i.e. Death, punishment -- destruction.
STRONGS NT 3639: ὄλεθροςὄλεθρος, ὄλεθρον (ὄλλυμι to destroy (perhaps (ὀλνυμι) allied to Latinvulnus)), from Homer down, rain, destruction, death: 1 Thessalonians 5:3; 1 Timothy 6:9; εἰς ὄλεθρον τῆς σαρκός, for the destruction of the flesh, said of the external ills and troubles by which the lusts of the flesh are subdued and destroyed, 1 Corinthians 5:5 (see παραδίδωμι, 2); equivalent to the loss of a life of blessedness after death, future misery, αἰώνιος (as 4 Macc. 10:15): 2 Thessalonians 1:9 (where L text ὀλέθριον, which see), cf. Wis. 1:12. STRONGS NT 3639a: ὀλιγοπιστίαὀλιγοπιστία, ὀλιγοπιστιας, ἡ, littleness of faith, little faith: Matthew 17:20 L T Tr WH, for R G ἀπιστία. (Several times in ecclesiastical and Byzantine writings.)