Crossword Genius

Principal uniform worn by fighting men born on base (6,3)

Ross

I believe the answer is:

number one

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

'principal' is the definition.
(both can mean the top)

'by fighting men born on base' is the wordplay.
'by' means one lot of letters go next to another.
'fighting men' becomes 'umber' (I can't explain this - if you can you should give a lot more credence to this answer).
'born' becomes 'n'.
'base' becomes 'e' (Euler's number - base of natural logarithms).
'umber' after 'n' is 'number'.
'number'+'on'+'e'='NUMBER ONE'

'uniform worn' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.

Can you help me to learn more?

(Other definitions for number one that I've seen before include "Wee" , "Informally and numerically, oneself" , "best record" , "Musical success" , "Informally the self, numerically speaking" .)

I've seen this clue in The Telegraph.
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.