Go with Mike after six (3)
I believe the answer is:
vim
'go' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'mike after six' is the wordplay.
'mike' becomes 'M' (phonetic alphabet: alpha, bravo, charlie etc.).
'after' means one lot of letters go next to another.
'six' becomes 'VI' (Roman numerals).
'm' after 'vi' is 'VIM'.
'with' is the link.
Can you help me to learn more?
(Other definitions for vim that I've seen before include "Liveliness" , "Pep and vigour" , "Exuberant vigour" , "Pep (informal)" , "Pizazz" .)