Administer oath of office without gravity, wearing a suede top hat (5,2)
I believe the answer is:
swear in
'administer' is the definition.
Although both the answer and definition are verbs in their base form, I can't understand how one could define the other.
'oath of office without gravity wearing a suede top hat' is the wordplay.
I cannot quite see how this works, but
'oath' could be 'swear' (I have seen 'Utter oath' mean 'swear' so perhaps 'oath' could also mean 'swear') and 'swear' is found in the answer.
'wearing' could be 'in' (as in being 'in' certain clothes) and 'in' is present in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for swear in that I've seen before include "Administer oath to one taking up office" , "Get into office" , "prepare to deliver evidence" , "Induct into office" , "Admit to office" .)