Reach a remarkable Titan (6)
I believe the answer is:
attain
'reach' is the definition.
(I've seen this before)
'a remarkable titan' is the wordplay.
'remarkable' is an anagram indicator.
'titan' is an anagram of 'ttain'.
'a'+'ttain'='ATTAIN'
(Other definitions for attain that I've seen before include "Arrive at, accomplish" , "Succeed in getting or doing" , "Reach with effort" , "Succeed in accomplishing; reach" , "Reach or gain" .)