Laying the ground work

"For if, after they have escaped the defilements of the world by the knowledge of the Lord and Savior Jesus Christ, they are again entangled in them and are overcome, the last state has become worse for them than the first." (2 Peter 2:20, NASB95)

"Εἰ γὰρ ἀποφυγόντες τὰ μιάσματα τοῦ κόσμου ἐν ἐπιγνώσει τοῦ Κυρίου καὶ Σωτῆρος Ἰησοῦ Χριστοῦ, τούτοις δὲ πάλιν ἐμπλακέντες ἡττῶνται, γέγονεν αὐτοῖς τὰ ἔσχατα χείρονα τῶν πρώτων." (2 Peter 2:20, Majority Text (Hodges/Farstad))

Vocabulary
Εἰ (G 1623) if: a marker of a condition, real, hypothetical, actual, or contrary to fact [1]

ἀποφυγόντες (G 668) escape: to flee. To flee away from, escape;[2] (LN 21.14) to become safe from danger by avoiding or escaping—‘to escape, to avoid.’[3]

μιάσματα (G 3393) defilements: The contamination of the world upon the godly as a result of living in it; the result of miasmós (G 3394), the act of polluting.[4] (LN 88.259) a state of being tainted or stained by evil.[5]

ἐπιγνώσει (G 1922) knowledge: noun from epiginṓskō (G 1921), to recognize. It is more intense. than gnṓsis (G 1108), knowledge, because it expresses a more thorough participation in the acquiring of knowledge on the part of the learner. In the NT, it often refers to knowledge which very powerfully influences the form of religious life, a knowledge laying claim to personal involvement. [6]

ἐμπλακέντες (G 1707) entangled: To braid in, interweave, entangle.[7] (LN 90.81) to become so involved in some activity as to experience severe restrictions as to what one can do.[8]

ἡπῶνται (G G 2274) overcome: less, inferior. To overcome or be overcome as in battle or in a lawsuit (2Pe 2:19-20); to be inferior (2Co 12:13).[9] (LN 88.134) to experience worse treatment—‘to be treated worse, to suffer more.’[10]

[1]Swanson, J. (1997). Dictionary of Biblical Languages with Semantic Domains : Greek (New Testament) (electronic ed.) (DBLG 1623, #1). Oak Harbor: Logos Research Systems, Inc.
[2] The Complete Word Study Dictionary New Testament.
[3]Louw, J. P., & Nida, E. A. (1996, c1989). Greek-English lexicon of the New Testament : Based on semantic domains (electronic ed. of the 2nd edition.) (1:239). New York: United Bible societies.
[4] The Complete Word Study Dictionary New Testament.
[5]Louw, J. P., & Nida, E. A. (1996, c1989). Greek-English lexicon of the New Testament : Based on semantic domains (electronic ed. of the 2nd edition.) (1:769). New York: United Bible societies.
[6] The Complete Word Study Dictionary New Testament.
[7] The Complete Word Study Dictionary New Testament.
[8]Louw, J. P., & Nida, E. A. (1996, c1989). Greek-English lexicon of the New Testament : Based on semantic domains (electronic ed. of the 2nd edition.) (1:808). New York: United Bible societies.
[9] The Complete Word Study Dictionary New Testament.
[10]Louw, J. P., & Nida, E. A. (1996, c1989). Greek-English lexicon of the New Testament: Based on semantic domains (electronic ed. of the 2nd edition.) (1:756). New York: United Bible societies.