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Webster 1828 Edition

adv.

With despite; maliciously; contemptuously.

Pray for them that despitefully use you. Matt. 5.

despitefully ‎(comparative more despitefully, superlative most despitefully)

In a despiteful manner; spitefully
- Bible, KJV, Luke 6:28
  Bless them that curse you, and pray for them which despitefully use you.