Not sensing central point about Frenchman (4)

I believe the answer is:

numb

I'm a little stuck... Click here to teach me more about this clue!

'not sensing central' is the definition.
I can't judge whether this definition defines the answer.

'point about frenchman' is the wordplay.
'point' becomes 'nub' (I've seen this before).
'about' means one lot of letters goes inside another.
'frenchman' becomes 'm' (abbreviation for Monsieur - like 'Mr').
'nub' placed around 'm' is 'NUMB'.

Can you help me to learn more?

(Other definitions for numb that I've seen before include "Without feeling" , "Deaden" , "Deprived of sensation" , "Deprived of feeling" , "Insensitive" .)

I've seen this clue in The Independent.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.