Party is on the way into Office (9)
I believe the answer is:
reception
'party' is the definition.
(reception is a kind of party)
'on the way into office' is the wordplay.
I cannot really see how this works, but
'on' could be 're' ('on' can be mean 'with reference to') and 're' is present in the answer.
'way' could be 'n' (Compass direction - North) and 'n' is present in the answer.
This explanation may well be incorrect...
'is' acts as a link.
Can you help me to learn more?
(Other definitions for reception that I've seen before include "Entrance for office" , "Formal function" , "Hotel entrance area" , "drinks party" , "at home" .)