Frank turned on number one cricketer? (6)
I believe the answer is:
opener
'number one cricketer?' is the definition.
'opener' can be an answer for 'cricketer?' (batsman who opens the batting). I'm not certain of the 'number one' bit.
'frank turned on' is the wordplay.
'frank' becomes 'open' (synonyms).
'turned' is a reversal indicator.
'on' becomes 're' (regarding).
're' back-to-front is 'er'.
'open'+'er'='OPENER'
Can you help me to learn more?
(Other definitions for opener that I've seen before include "Batsman number one" , "First going in to bat" , "Kitchen item" , "First event in a series" , "introduction" .)