Noble’s answer queen dismissed (5)
I believe the answer is:
count
'noble's' is the definition.
(count is a kind of noble)
'answer queen dismissed' is the wordplay.
'answer' becomes 'counter' (counter can mean an answer or reply).
'queen' becomes 'ER' (short for Elizabeth Regina ie Queen Elizabeth).
'dismissed' suggests deleting specific letters.
'counter' with 'er' removed is 'COUNT'.
(Other definitions for count that I've seen before include "consideration" , "Sum up" , "Nobleman; tally" , "Titled man" , "Matter to consider" .)