Crossword Genius

First nine letters of alphabet written up - culminating in this? (4)

Ross

I believe the answer is:

iota

'first nine' is the definition.
The definition and answer can be both quantities as well as being singular nouns.
Maybe they are linked in a way I don't understand?

'letters of alphabet written up culminating in this?' is the wordplay.
I cannot quite see how this works, but
'of' could be 'o' and 'o' is found in the answer.
The remaining letters 'ita' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...

(Other definitions for iota that I've seen before include "Scintilla" , "Tiniest scrap" , "Tiny piece" , "'Very small amount, jot (4)'" , "Trace" .)

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.