unusurping

前缀

词干

后缀

un-: (added to adjectives or past participles) not · (added to nouns) lack of
-ing: Used to form nouns or noun-like words (or elements of noun phrases) from verbs, denoting the act of doing something, an action, or the embodiment of an action. · Used to form nouns denoting materials or systems of objects which are used or employed in an action, or considered collectively.

From un- +‎ usurp +‎ -ing.