A lemur monkeying around after noon or 1? (7)

I believe the answer is:
numeral
'1?' is the definition.
Although both the answer and definition are adjectives, I don't understand how they can define each other.
'a lemur monkeying around after noon' is the wordplay.
I cannot quite understand how this works, but
'a' is present in the answer.
an anagram of 'lemur' is 'umerl' which is present in the left over letters.
'noon' could be 'n' (abbreviation for noon) and 'n' is found within the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'or' acts as a link.
Can you help me to learn more?
(Other definitions for numeral that I've seen before include "Figure representing a value" , "1, 2, 3, say" , "Symbol used to express quantity" , "Eg, two or seven" , "Symbol for number" .)
