Lost first plum opportunity to get involved again (2-6)
I believe the answer is:
re-engage
'lost first plum opportunity' is the definition.
The definition suggests a singular noun which matches the answer.
'get involved again' is the wordplay.
I cannot quite understand how this works, but
'get' could be 'engage' (engaging is a kind of getting) and 'engage' is found within the answer.
'again' could be 're' (prefix meaning 'again') and 're' is located in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
'to' acts as a link.
Can you help me to learn more?
(Other definitions for re-engage that I've seen before include "Get back on job" , "Employ or hire again" .)