Word Summary
phtheirō: to destroy, corrupt, spoil
Original Word: φθείρω
Transliteration: phtheirō
Phonetic Spelling: (fthi'-ro)
Part of Speech: Verb
Short Definition: to destroy, corrupt, spoil
Meaning: to destroy, corrupt, spoil
Strong's Concordance
corrupt, defile, destroy.

Probably strengthened from phthio (to pine or waste); properly, to shrivel or wither, i.e. To spoil (by any process) or (generally) to ruin (especially figuratively, by moral influences, to deprave) -- corrupt (self), defile, destroy.

Thayer's Greek Lexicon
STRONGS NT 5351: φθείρω

φθείρω; future φθερῶ; 1 aorist ἐφθειρα; passive, present φθείρομαι; 2 aorist ἐφθάρην; 2 future φθαρήσομαι; (akin to German verderben); the Sept. for שִׁחֵת; (from Homer down); to corrupt, to destroy: properly, τόν ναόν τοῦ Θεοῦ (in the opinion of the Jews the temple was corrupted, or 'destroyed', when anyone defiled or in the slightest degree damaged anything in it, or if its guardians neglected their duties; cf. Deyling, Observations, sacrae, vol. ii, p. 505ff), dropping the figure, to lead away a Christian church from that state of knowledge and holiness in which it ought to abide, 1 Corinthians 3:17a; τινα, to punish with death, 1 Corinthians 3:17{b}; equivalent to to bring to want or beggary (cf. our ruin (A. V. corrupt)), 2 Corinthians 7:2; passive, to be destroyed, to perish: ἐν τίνι, by a thing, Jude 1:10; ἐν with a dative denoting the condition, ἐν τῇ φθορά αὐτῶν, 2 Peter 2:12 L T Tr WH. in an ethical sense, to corrupt, deprave: φθείρουσιν ἔθη χρηστά ὁμιλίαι κακαί (a saying of Menander (see ἦθος, 2), which seems to have passed into a proverb (see Wetstein at the passage; Gataker, Advers. misc. l. i. c. 1, p. 174f)), 1 Corinthians 15:33; the character of the inhabitants of the earth, Revelation 19:2; passive, φθείρομαι ἀπό τίνος, to be so corrupted as to fall away from a thing (see ἀπό, I. 3 d.), 2 Corinthians 11:3; φθειρόμενον κατά τάς ἐπιθυμίας (R. V. waxeth corrupt etc.), Ephesians 4:22. (Compare: διαφθείρω, καταφθείρω.)