Still going north with the first mate (4)
I believe the answer is:
even
'still' is the definition.
(synonyms)
'going north with the first mate' is the wordplay.
'going north' becomes 'n' (synonyms. I am not sure about the 'going' bit.).
'with' is a charade indicator (letters next to each other).
'the first mate' becomes 'eve' (Adam's mate in the Bible).
'n' after 'eve' is 'EVEN'.
Can you help me to learn more?
(Other definitions for even that I've seen before include "Like 2018 but not 2017" , "Smooth, level" , "Equally balanced; level" , "Nearly" , "end of the day, reading poetry" .)