Girl with a lot of go (3)
I believe the answer is:
vim
'go' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'girl with a lot' is the wordplay.
'girl' becomes 'Vi' (short for Violet).
'with' is a charade indicator (letters next to each other).
'a lot' becomes 'm' ().
'vi'+'m'='VIM'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for vim that I've seen before include "Energy and vigour" , "Pizazz" , "Pep and vigour" , "Pep (informal)" , "Exuberant vigour" .)