Enter the office uninvited? (5)
I believe the answer is:
usurp
'enter' is the definition.
Although both the answer and definition are verbs in their base form, I cannot see how one could define the other.
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for usurp that I've seen before include "Supplant (someone in power)" , "Commandeer" , "Arrogate" , "Dethrone" , "Assume by force" .)