22 across
Whistler
recalled
mother
having
little
time
for
theorist
(6)
Whistler recalled mother having little time for theorist (6)
hints
0
checks
0
hints
The definition is at the end of the clue.
How the clue works
Look at theorist at the end — that's your definition, pointing to the famous mathematician. Whistler gives you REF (as in a referee), and recalled tells you to reverse it to get FER, then add MA for mother, and finally T as the abbreviation for a little time.