Titan meant to change acquisition (10)
I believe the answer is:
'acquisition' is the definition.
(I know that acquisition can be written as attainment)
'titan meant to change' is the wordplay.
'to change' indicates an anagram.
'titanmeant' anagrammed gives 'ATTAINMENT'.
(Other definitions for attainment that I've seen before include "The achievement (of a goal)" , "Feat achieved" , "Act of achieving something" , "Laudable exploit" , "Skill, achievement" .)