Mean the figure one has in mind, mostly (6)
I believe the answer is:
intend
'mean' is the definition.
(to intend to something is to mean it)
'the figure one has in mind mostly' is the wordplay.
'the figure' becomes 'd' (I've seen this in other clues).
'one has' is a charade indicator (letters next to each other).
'mind' becomes 'tend' (to tend is to look after or mind somebody).
'mostly' means to remove the last letter (most but not all of the word).
'tend' with its final letter removed is 'ten'.
'in'+'ten'='inten'
'd' after 'inten' is 'INTEND'.
(Other definitions for intend that I've seen before include "Have as one's plan" , "Mean (to do something)" , "Contemplate - mean - plan" , "1 dn [DESIGN]" , "Plan, propose" .)