Arrive to join me and the commander (4)
I believe the answer is:
come
'arrive' is the definition.
(coming is a kind of arriving)
'me and the commander' is the wordplay.
'and' means one lot of letters go next to another.
'the commander' becomes 'CO' (commanding officer).
'me' after 'co' is 'COME'.
'to join' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for come that I've seen before include "' - - fly with me'" , "Rude aggressive youth" , "Approach" , "Arrive" , "Turn up" .)