A submarine captain, first person to attempt meteorological technique (10)
I believe the answer is:
anemometry
'meteorological technique' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'a submarine captain first person to attempt' is the wordplay.
'submarine captain' becomes 'nemo' (character from 20,000 Leagues Under the Sea).
'first person' becomes 'me' (first-person pronoun).
'to attempt' becomes 'try' (synonyms).
'a'+'nemo'+'me'+'try'='ANEMOMETRY'
Can you help me to learn more?
(Other definitions for anemometry that I've seen before include "Measuring wind speed" , "wind instrument?" .)