Have an ambition of rents rising in emergency accommodation (6)
I believe the answer is:
aspire
'have an ambition' is the definition.
(I've seen this before)
'rents rising in emergency accommodation' is the wordplay.
'rents' becomes 'rips' ('rip' can be a synonym of 'rent').
'rising' says the letters should be written in reverse (in a down clue, letters go up).
'in' indicates putting letters inside.
'emergency accommodation' becomes 'ae' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'rips' back-to-front is 'spir'.
'spir' going within 'ae' is 'ASPIRE'.
'of' is the link.
Can you help me to learn more?
(Other definitions for aspire that I've seen before include "Have lofty aims" , "Set your sights on" , "Aim (for higher things)" , "Aim, have an ambitious plan" , "Wish to rise (to)" .)