different between disownment vs disavowment

English

disown +? -ment

disownment (countable and uncountable, plural disownments)

disavow +? -ment

disavowment (usually uncountable, plural disavowments)

disavowal
- January 17 1637, Henry Wotton, letter to the Right Worthy Provost and Professor Regius of Divinity in Cambridge
  For as touching the Tridentine History, His Holiness (?ayes the Cardinal ) will not press you to any disavowment thereof, though you have an Epistle before the Original Edition

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