Definify.com

Webster 1828 Edition

adv.

In opposition to natural feelings and sentiments.

unnaturally ‎(not comparable)

In an unnatural manner.
- 1918, W. B. Maxwell, chapter 22, in The Mirror and the Lamp:
  Not unnaturally, “Auntie” took this communication in bad part. Thus outraged, she showed herself to be a bold as well as a furious virago. Next day she found her way to their lodgings and tried to recover her ward by the hair of the head.