Visualising one mother and her ruin in Gabon (9)
I believe the answer is:
imagining
'visualising' is the definition.
(to imagine is to visualise)
'one mother and her ruin in gabon' is the wordplay.
I cannot quite understand how this works, but
'one' could be 'i' (Roman numeral) and 'i' is found in the answer.
'mother' could be 'ma' (ma can mean mother) and 'ma' is present in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is found in the answer.
'in' is found in the answer.
The remaining letters 'gig' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
(Other definitions for imagining that I've seen before include "Fancying" , "Fantasising" , "Supposing, assuming" , "Thinking up" , "illusion?" .)