#4418 πτέρνα pterna {pter'-nah}

 of uncertain derivation; TDNT - n/a; n f

—Greek Word Study (Transliteration-Pronunciation Etymology & Grammar)

 1) the heel (of the foot)
 2) to lift up the heel against one
    2a) to injure one by trickery (figure borrowed either from
        kicking, or from a wrestler tripping up his antagonist)

—Thayer's (New Testament Greek-English Lexicon)

—Strong's (Greek Dictionary of the New Testament)

—NAS Exhaustive Concordance of the Bible with Hebrew-Aramaic and Greek Dictionaries

 AV - heel 1; 1

—Exhaustive Concordance (KJV Translation Frequency & Location)