In a manner differing from what is natural or normal; not in accordance with the regular course of nature; unnaturally, abnormally. Obsolete.

In an accidental or chance manner; accidentally, by chance (contextually: by mischance). (In modern use only as an occasional spelling variant of…

In an unnatural or extraordinary manner. Obsolete.

unnaturally, against nature.

In a manner differing from what is natural or normal; to an unnatural degree; abnormally, unusually.

= monstrously, adv.

Abnormally; to an abnormal extent. In weakened sense: exceedingly, extraordinarily.

In a preternatural manner; abnormally, extraordinarily; (in weakened use) unusually.