Occasionally, mind recalls model (5)
I believe the answer is:
ideal
'model' is the definition.
(ideal can mean model or perfect)
'occasionally mind recalls' is the wordplay.
'occasionally' means one should take alternating letters (letters taken at regular intervals or occasions).
'mind'+'recalls'='mindrecalls'
The alternate letters of 'mindrecalls' are 'IDEAL'.
(Other definitions for ideal that I've seen before include "Standard of perfection or excellence" , "fanciful" , "existing only in imagination" , "A deli (anag.)" , "Perfect but perhaps unlikely to become reality" .)